Assuming that the MAC is stable and not giving any issues I would try and see why the XP VM is crashing and at the very least re-install VMWare Tools on XP as that is what is required for copy and paste between the host and guest OS.
Look in Event Viewer in XP to see if you can see what is going wrong ... click Start, then right click My Computer and then click Manage then click on Event viewer ...
Perpahs try running a virus scanner or malware applications in XP if you think it might be infected.
If all esle fails try and repair the XP virtual machine from your XP CD ...