Mouse and keyboard temporarily lock up

System specs:

Processor: AMD Athlon 64 X2 Dual Core Processor 5000+
RAM: 2 GB
Graphics card: GeForce 8600 GT
OS: Microsoft Windows XP Professional Service Pack 2 (build 2600)

Madcows sweps and npc spawn platforms are my only installed addons

Okay, my biggest issue is when I use the Q-menu, i’ll have a split second to move the mouse around, then everything just freezes up and I have to wait several minutes after releasing Q to move around again. And when in the Q-menu if I start clicking repeatedly my mobo starts beeping at me. I’ve tried fixing this problem myself and have found no solution.
Also, if my FPS drops below a certain point (don’t know for sure but its around 30 fps) and I try to sprint and turn my keyboard and mouse lock up and I’ll keep sprinting for a little while with no control.
Please help.