2) Do you have a seagate momentus XT hard drive?
3) Tempoarily disable it inside the VM and see if the behavior stops
4) Disk utility is unreliable - use smart utility from voltain's software
and I missed the big one - did you copy over the VM, or did you convert a physical machine? If the latter, that almost always results in a bloated, unstable VM. Since you have to purchase a windows license anyway (OEM licenses can't be legally virtualized), you're better off building a VM from scratch.
10.6.8 indicates a pretty old mac, so if you've never replaced the hard drive, that's a good shot at the culprit.
FWIW, 10.6 is no longer actively supported by Apple.
