I have a similar issue. Vista freezes for a few minutes, then acts as if nothing happened. I am getting a DLLHost.exe stop message in the Reliability and Performance Monitor. I have had Perfmon running when it happens and not even a blip in any of the counters. My version of Vista is Ultimate (6.0.6000). My computer specs:

CPU: P4 3.2 ghz "640"
RAM: 2 gb DDR2 667
Video: Vision Tek X1300XT PCIe 256 mg
Drive0: SATA 200 gb
Drive1: SATA 80 gb
DVD0: Sony DVD
DVD1: Memorex DVD Burner 16x Dual Layer
MB: ECS RS400-A

Any ideas?

Thanks,

Tom