--- tk8.5.1/macosx/tkMacOSXScrlbr.c~	2008-05-14 22:13:36.000000000 -0400
+++ tk8.5.1/macosx/tkMacOSXScrlbr.c	2008-08-05 19:00:44.000000000 -0400
@@ -565,11 +565,11 @@
     MacScrollbar *macScrollPtr = (MacScrollbar *) scrollPtr;
     Tcl_DString cmdString;
     int origValue, variant;
-    short trackBarSize;
+    short trackBarSize, pixDiff;
     double oldFirstFraction, newFirstFraction;
     char valueString[40];
     Point currentPoint = { 0, 0 };
-    Rect trackRect;
+    Rect ctrlRect;
     Tcl_Interp *interp;
     MouseTrackingResult trackingResult;
     OSStatus err;
@@ -580,20 +580,18 @@
 
     Tcl_DStringInit(&cmdString);
     origValue = GetControl32BitValue(macScrollPtr->sbHandle);
-    GetControlBounds(macScrollPtr->sbHandle, &trackRect);
+    GetControlBounds(macScrollPtr->sbHandle, &ctrlRect);
 
     if (scrollPtr->vertical) {
-	variant = (trackRect.right - trackRect.left) < metrics[0].width ? 1 : 0;
-	trackBarSize = trackRect.bottom - trackRect.top -
+	variant = (ctrlRect.right - ctrlRect.left) < metrics[0].width ? 1 : 0;
+	trackBarSize = ctrlRect.bottom - ctrlRect.top -
 		metrics[variant].topArrowHeight -
 		metrics[variant].bottomArrowHeight;
-	InsetRect(&trackRect, -25, -113);
     } else {
-	variant = (trackRect.bottom - trackRect.top) < metrics[0].width ? 1 : 0;
-	trackBarSize = trackRect.right - trackRect.left -
+	variant = (ctrlRect.bottom - ctrlRect.top) < metrics[0].width ? 1 : 0;
+	trackBarSize = ctrlRect.right - ctrlRect.left -
 		metrics[variant].topArrowHeight -
 		metrics[variant].bottomArrowHeight;
-	InsetRect(&trackRect, -113, -25);
     }
 
     /*
@@ -620,28 +618,19 @@
 	   /*
 	    * Calculate where the scrollbar should move to, based on
 	    * where the mouse button was pressed and where the scrollbar
-	    * initially was at that time. Note that PtInRect() will
-	    * return false if currentPoint or trackRect are not in
-	    * is not in current graphics port, which may happen if any
-	    * of the waiting idle events change the port (e.g. with
-	    * SetPort()) but fail to restore it before returning and the
-	    * scrollbar will lock in place.
+	    * initially was at that time.
 	    */
 	    newFirstFraction = oldFirstFraction;
-	    if (PtInRect(currentPoint, &trackRect)) {
-		short pixDiff;
-
-		if (scrollPtr->vertical) {
-		    pixDiff = currentPoint.v - mouseDownPoint.v;
-		} else {
-		    pixDiff = currentPoint.h - mouseDownPoint.h;
-		}
-		newFirstFraction += (double)pixDiff / trackBarSize;
-		if (newFirstFraction > 1.0) {
-		    newFirstFraction = 1.0;
-		} else if (newFirstFraction < 0.0) {
-		    newFirstFraction = 0.0;
-		}
+	    if (scrollPtr->vertical) {
+		pixDiff = currentPoint.v - mouseDownPoint.v;
+	    } else {
+		pixDiff = currentPoint.h - mouseDownPoint.h;
+	    }
+	    newFirstFraction += (double)pixDiff / trackBarSize;
+	    if (newFirstFraction > 1.0) {
+		newFirstFraction = 1.0;
+	    } else if (newFirstFraction < 0.0) {
+		newFirstFraction = 0.0;
 	    }
 
 	    /*
