It seems as if my button control cannot be clicked at some areas of it.
Here's a picture: Untitled.png(http://img856.imageshack.us/img856/5981/48366364.png)

I've marked the area where one CANNOT press the button, with a yellow square.
These buttons are distinct from all other controls - meaning that they are NOT overlapped.
I have made sure to set the Icon size to EXACTLY the same as the button size, just in case.

Now, here's the part i get a bit confused. If i move my buttons(both of them) to another place than their current location(ie: the bottom of my app's Z-Y coordinates) this problem doesn't occur.
I've also tested this on other PC's(though, only on Windows 7, 64bit..)

If anyone has any idea what might cause this 'funny' behavior, I'd appreciate an explanation - and possibly some help to fix it.