>I'm fairly certain I've seen it on things besides the 'X'. I think I've seen it on menu items. I need to pay more attention. It seems to be a bug, and it would be nice to have it fixed.

Any button in windows will have similar behaviour.. Sometimes it's a quick way to not press a button that you accidentally clicked on - If you slide teh pointer off the button before releasing the mouse button, the button will not actually click. I've noticed this behaviour since way way back...

---
Jonathan Chan