diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 49256f49..1917b699 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,5 +1,13 @@
 # PyGPSClient Release Notes
 
+### RELEASE 1.6.10
+
+1. Minor enhancements to UBX Config Dialog confirmation signalling. 
+1. Amend CFG-VALSET/GET/DEL Configuration Interface panel; X-type attributes (`X004`, `X008`, etc.) are now entered in 
+conventional hexadecimal integer notation rather than little-endian hex strings, consistent with values illustrated in the Interface
+Specifications e.g. value for CFG_SBAS_PRNSCANMASK (`X008`) would now be entered `0x000000000003ab88` rather than `88ab030000000000`.
+1. Make 'Check for update on startup' 'opt-in' rather than 'opt-out'. Setting available via About dialog.
+
 ### RELEASE 1.6.9
 
 1. Add manually-editable `resizeable_dialog_b` configuration setting as a workaround for screen scaling issues on some platforms (e.g. Ubuntu Wayland). Fixes #250.
diff --git a/pyproject.toml b/pyproject.toml
index 95b01984..488f567e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -55,6 +55,7 @@ dependencies = [
     "pygnssutils>=1.2.1",
     "pyunigps>=1.0.0",
     "pynmeagps>=1.1.4",
+    "pyubx2>=1.3.1",
 ]
 
 [project.scripts]
diff --git a/src/pygpsclient/_version.py b/src/pygpsclient/_version.py
index 160a57ea..a97d72e2 100644
--- a/src/pygpsclient/_version.py
+++ b/src/pygpsclient/_version.py
@@ -8,4 +8,4 @@
 :license: BSD 3-Clause
 """
 
-__version__ = "1.6.9"
+__version__ = "1.6.10"
diff --git a/src/pygpsclient/configuration.py b/src/pygpsclient/configuration.py
index 63a6834f..2bfad4b3 100644
--- a/src/pygpsclient/configuration.py
+++ b/src/pygpsclient/configuration.py
@@ -107,7 +107,7 @@ def __init__(self, app):
             "showsettings_b": 1,
             "docksettings_b": 1,
             **self.widget_config,
-            "checkforupdate_b": 1,
+            "checkforupdate_b": 0,
             "transient_dialog_b": 1,  # whether pop-up dialogs are on top of main app window
             "resizeable_dialog_b": 0,  # whether pop-up dialogs are all resizeable
             "guiupdateinterval_f": GUI_UPDATE_INTERVAL,  # GUI widget update interval in seconds
diff --git a/src/pygpsclient/helpers.py b/src/pygpsclient/helpers.py
index 20b696c3..1c35ff92 100644
--- a/src/pygpsclient/helpers.py
+++ b/src/pygpsclient/helpers.py
@@ -1483,6 +1483,23 @@ def valid_geom(geom: str) -> bool:
     return regexgeom.match(geom) is not None
 
 
+def valid_hex(val: str, *args) -> bool:
+    """
+    Validate hex string in Entry field.
+
+    :param str val: hexadecimal value
+    :return: Valid/Invalid
+    :rtype: bool
+    """
+
+    try:
+        atts = args[0]
+        int.to_bytes(int(val, 16), atts, "little")
+        return True
+    except (TypeError, ValueError, OverflowError):
+        return False
+
+
 def xy2ll(width: int, height: int, bounds: Area, xy: tuple) -> Point | NoneType:
     """
     Convert canvas x/y to lat/lon.
diff --git a/src/pygpsclient/ubx_cfgval_frame.py b/src/pygpsclient/ubx_cfgval_frame.py
index 0cd2b181..91ec1a28 100644
--- a/src/pygpsclient/ubx_cfgval_frame.py
+++ b/src/pygpsclient/ubx_cfgval_frame.py
@@ -41,6 +41,7 @@
 
 from pygpsclient.globals import (
     ERRCOL,
+    ICON_BLANK,
     ICON_CONFIRMED,
     ICON_PENDING,
     ICON_SEND,
@@ -50,10 +51,12 @@
     TRACEMODE_WRITE,
     UBX_CFGVAL,
     VALBOOL,
+    VALCUSTOM,
     VALFLOAT,
     VALINT,
     VALNONBLANK,
 )
+from pygpsclient.helpers import valid_hex
 
 VALSET = 0
 VALDEL = 1
@@ -94,6 +97,7 @@ def __init__(self, app: Frame, parent: Frame, *args, **kwargs):
         self._img_pending = ImageTk.PhotoImage(Image.open(ICON_PENDING))
         self._img_confirmed = ImageTk.PhotoImage(Image.open(ICON_CONFIRMED))
         self._img_warn = ImageTk.PhotoImage(Image.open(ICON_WARNING))
+        self._img_blank = ImageTk.PhotoImage(Image.open(ICON_BLANK))
         self._cfgval_cat = None
         self._cfgval_keyname = None
         self._cfgval_keyid = None
@@ -257,6 +261,7 @@ def reset(self):
         for i, cat in enumerate(cdb_cats):
             self._lbx_cat.insert(i, cat)
         self._cfgmode.set(2)
+        self._lbl_send_command.config(image=self._img_blank)
 
     def _on_select_mode(self, *args, **kwargs):  # pylint: disable=unused-argument
         """
@@ -267,6 +272,7 @@ def _on_select_mode(self, *args, **kwargs):  # pylint: disable=unused-argument
             self._ent_val.config(state=NORMAL)
         else:
             self._ent_val.config(state=READONLY)
+        self._lbl_send_command.config(image=self._img_blank)
 
     def _on_select_cat(self, *args, **kwargs):  # pylint: disable=unused-argument
         """
@@ -285,6 +291,7 @@ def _on_select_cat(self, *args, **kwargs):  # pylint: disable=unused-argument
                 self._lbx_parm.insert(idx, keyname)
                 idx += 1
         self._cfgval.set("")
+        self._lbl_send_command.config(image=self._img_blank)
 
     def _on_select_parm(self, *args, **kwargs):  # pylint: disable=unused-argument
         """
@@ -299,6 +306,7 @@ def _on_select_parm(self, *args, **kwargs):  # pylint: disable=unused-argument
             self._cfgkeyid.set(hex(keyid))
             self._cfgatt.set(att)
             self._cfgval.set("")
+            self._lbl_send_command.config(image=self._img_blank)
         except TclError:
             pass
 
@@ -307,6 +315,7 @@ def _on_send_config(self, *args, **kwargs):  # pylint: disable=unused-argument
         Config interface send button has been clicked.
         """
 
+        self._lbl_send_command.config(image=self._img_blank)
         if self._cfgval_keyname is not None:
             if self._cfgmode.get() == VALSET:
                 self._do_valset()
@@ -341,12 +350,15 @@ def _do_valset(self):
             layers = 1
         try:
             if att in ("C", "X"):  # byte or char
-                self._ent_val.validate(VALNONBLANK)
-                if len(val) == atts * 2:  # 2 hex chars per byte
-                    val = bytearray.fromhex(val)
-                else:
-                    valid = False
-
+                valid = self._ent_val.validate(
+                    VALCUSTOM,
+                    func=valid_hex,
+                    args=[
+                        atts,
+                    ],
+                )
+                if valid:
+                    val = int.to_bytes(int(val, 16), atts, "little")
             elif att in ("E", "U"):  # unsigned integer
                 self._ent_val.validate(VALINT)
                 val = int(val)
@@ -451,7 +463,9 @@ def update_status(self, msg: UBXMessage):  # pylint: disable=unused-argument
             val = getattr(msg, self._cfgval_keyname, None)
             if val is not None:
                 if isinstance(val, bytes):
-                    val = val.hex()
+                    atts = attsiz(self._cfgatt.get())
+                    vali = int.from_bytes(val, "little")
+                    val = f"0x{vali:0{atts*2}x}"
                 self._cfgval.set(val)
             self.__container.status_label = ("CFG-VALGET GET message received", OKCOL)
 
diff --git a/tests/test_static.py b/tests/test_static.py
index 4567bc4c..90ed7898 100644
--- a/tests/test_static.py
+++ b/tests/test_static.py
@@ -77,6 +77,7 @@
     unused_sats,
     val2sphp,
     valid_geom,
+    valid_hex,
     xy2ll,
 )
 from pygpsclient.mapquest_handler import (
@@ -963,6 +964,15 @@ def testhdg2yaw(self):
         self.assertEqual(hdg2yaw(375.0),15.0)
         self.assertEqual(hdg2yaw(715.0),-5.0)
 
+    def testvalidhex(self):
+
+        self.assertTrue(valid_hex("0x11223344", 4))
+        self.assertFalse(valid_hex("0x112233zz", 4))
+        self.assertFalse(valid_hex("0x1122334455667788", 4))
+        self.assertTrue(valid_hex("0x1122334455667788", 8))
+        self.assertFalse(valid_hex("asdfttwergazz", 4))
+        self.assertFalse(valid_hex("", 4))
+
 if __name__ == "__main__":
     # import sys;sys.argv = ['', 'Test.testName']
     unittest.main()