R61 Freezes but mouse still functions

[dt8300]

I was recently forced to reload Vista via the Thinkvantage due to a Turbo memory & Hybrid problem. Since then I have all the latest MS updates including SP2 as well as all Lenovo updates. Somewhere between reloading Vista & installing Lenovo updates my R61 has developed the annoying trait of freezing after about an hour. The mouse pointer still moves across the screen, however, keyboard, right & left mouse button are unresponsive as well as the hard drive activity indicator shows NO activity. Log files show no data at the time of freezing. I've ran Thinkvantage hardware tests & all have passed. I have run chkdsk /r two times which takes more than an hour & it finishes fine so I am quite convinced this is a driver issue with either Lenovo or MS. I would tend to think Lenovo after my most recent Turbo driver issue as well as few previous Lenovo driver issues concerning OSD, the inability to run chkdsk, etc... Any idea's or suggestions since I truly dread the idea of randomly disabling services & reinstalling drivers etc.
Thanks!
Doug