My PC has developed a strange problem in that my mouse pointer disappears when it is placed over certain apps. There doesn't seem to be a reason why the problem starts on any given day. Typically it will become invisible over some of the core apps that I use such as Excel, Outlook, Firefox etc but will appear if I move it down to the Windows taskbar. Other apps such as TextPad do not seem to be affected and the mouse is visible when hovering over them.
Quitting and restarting the affected apps seems to help a little, however the pointer soon disappears again. It is very frustrating and I am resorting to using the ctrl key to locate the pointer (using the Mouse control panel settings to turn this feature on).
I don't think I have changed any software configurations recently that could have caused this. I am using Windows XP.