Index: macosx/tkMacOSXClipboard.c
==================================================================
--- macosx/tkMacOSXClipboard.c
+++ macosx/tkMacOSXClipboard.c
@@ -71,11 +71,10 @@
 	    changeCount) {
 	TkDisplay *dispPtr = TkGetDisplayList();
 
 	if (dispPtr) {
 	    XEvent event;
-
 	    event.xany.type = SelectionClear;
 	    event.xany.serial = NextRequest(Tk_Display(clipboardOwner));
 	    event.xany.send_event = False;
 	    event.xany.window = Tk_WindowId(clipboardOwner);
 	    event.xany.display = Tk_Display(clipboardOwner);
@@ -123,12 +122,14 @@
     ClientData clientData)	/* Arbitrary value to pass to proc. */
 {
     int result = TCL_ERROR;
     TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr;
 
-    if (dispPtr && selection == dispPtr->clipboardAtom && (target == XA_STRING
-	    || target == dispPtr->utf8Atom)) {
+    int haveExternalClip = ([[NSPasteboard generalPasteboard] changeCount] != changeCount);
+    if (dispPtr && (haveExternalClip || dispPtr->clipboardActive)
+	        && selection == dispPtr->clipboardAtom
+	        && (target == XA_STRING || target == dispPtr->utf8Atom)) {
 	NSString *string = nil;
 	NSPasteboard *pb = [NSPasteboard generalPasteboard];
 	NSString *type = [pb availableTypeFromArray:[NSArray arrayWithObject:
 		NSStringPboardType]];
 
@@ -174,11 +175,10 @@
 
     if (dispPtr && selection == dispPtr->clipboardAtom) {
 	clipboardOwner = owner ? Tk_IdToWindow(display, owner) : NULL;
 	if (!dispPtr->clipboardActive) {
 	    NSPasteboard *pb = [NSPasteboard generalPasteboard];
-
 	    changeCount = [pb declareTypes:[NSArray array] owner:NSApp];
 	}
     }
     return Success;
 }

Index: macosx/tkMacOSXDialog.c
==================================================================
--- macosx/tkMacOSXDialog.c
+++ macosx/tkMacOSXDialog.c
@@ -115,11 +115,11 @@
 };
 enum alertIconOptions {
     ICON_ERROR, ICON_INFO, ICON_QUESTION, ICON_WARNING
 };
 static const char *const alertButtonStrings[] = {
-    "abort", "retry", "ignore", "ok", "cancel", "yes", "no", NULL
+    "abort", "retry", "ignore", "ok", "cancel", "no", "yes", NULL
 };
 
 static const NSString *const alertButtonNames[][3] = {
     [TYPE_ABORTRETRYIGNORE] =   {@"Abort", @"Retry", @"Ignore"},
     [TYPE_OK] =			{@"OK"},