I will try to reproduce the issue with the setup that you mentioned.
But MVT was successfully tested on both XP SP2 and SP3.
Just to clarify a few things
1. MVT was deployed through EPO onto XP SP2 machines ?
2. Are you running MVT on client machine from Start->Programs->McAfee->McAfee Virtual Technician or MVT task from EPO ?
3. Which patch of Agent 4.5 is installed on client machine ?
4. Which version of Windows 2008 is been used is it Enterprise ? Then as well 32 or 64 bit and what SP is installed ?
5. For the crash then you ran MVT from Start->Programs->McAfee->McAfee Virtual Technician on client machine.
Are you viewing MVT final report and MVT Problem Log from the UI or selecting them from Start->Programs->McAfee-> ?
6. Is the system crashing happening when you run MVT diagnostic task on client machine and then select MVT final report and MVT Problem Log from Start->Programs->McAfee-> ?