Mouse Cursor Crazy in FSX window

I run FSX Accel + under Windows 7 64-bit. I run FSX in the Windows mode. In the last couple of days my mouse (USB mouse)cursor goes crazy within the FSX windows. The cursor appears to blink rapidly making it harder to access a mouse button. The cursor only blinks in the FSX window. Once you move the corsor out of that window, it works fine - no blink. I've tried resetting the USB plug. This didn't help. I tried restarting the OS - that didn't help.

Has anyone else experienced this rapid blinking when they fly?

Thanks

Frank