VmWare Player Windows XP Performance

I am having a huge performance problem with my Windows Xp virtual machine. The mouse kind of stutters and disappears, then reappears, rapidly, repeatedly. It is crawling. The strange thing is that it starts out fast, but the performance degrades after a while. I tried actually setting no page file on the host. That worked for a while. I have all my host PC related performance options set to maximum performance. My host has 4GB of memory and a 2 Ghz core 2 duo with VT option enabled in the bios. The XP machine is a clean install, and works great on another computer with the exact same specs (we ordered 2 of the same laptops). The other laptop has Windows 7 build 7100, this one has Windows Vista SP1. I need help, this is critical.