Thanks for the replies and suggestions. So far I have applied only this hotfix
http://support.microsoft.com/kb/894391 as told by bigfellla in the post above. I have only ran my PC for about 3 hours since then and the problem has not resurfaced yet. If it comes back again as it used to earlier then i'll need further help for sure.
Waiting for inputs from TSF staff as well on this issue.
Thanks