MouseGoddess, I'd try reinstalling CursorFX, or maybe even try a different mouse. I use CursorFX on Windows 8.1 with zero problems.
Just suggestions. I had a mouse to do that. It was a wireless mouse and what fixed it was to move the mouse closer to the receiver. I had to run an extension USB cable.
Anyway, I hope you get it fixed, but I don't think it's a Windows 8.1 thing.