It's set to grow up to 3GB, so I doubt it's that. It can't hurt anything to try it, though. Follow these steps to expand and "clean up" your page file:

• Go into virtual memory and choose "No paging file." Click Set, then okay. It will make you reboot.
• Run defrag on the HD to host the paging file
• Go into virtual memory, select Custom size, and set both the minimum and maximum to 4096. Click Set, then okay. It will make you reboot.

You will then have a defragged, 4GB, fixed location page file. If this does not solve your problem, it's not your virtual memory.