I just want to chime in that I'm having this same exact problem. I'm running 10.7.2, which was combo upgraded from a clean install of 10.7.0.
System specs:
i5-2500K
using built in Intel HD 3000 with the max 480mb set in bios registering within osx as 512mb
16GB RAM
1 TB OS Drive
2TB storage internal drive
Gigabyte GA-Z68A-D3H-B3 mobo with F10 bios version.
I'm using dual monitors, one into DVI one into HDMI, if that matters.
Also used macmini5,1 in multibeast
Installed Lion with multibeast using user DSDT for my specific mobo and version -- no other problems except this freezing issue AND some small lines across the screen every now and then, which go away with closing/reopening the window thye're in.
When my computer freezes, the mouse can still be moved, if left alone the screes will go into power save and moving the mouse wakes them back up. Interestingly background processes are still working (i cna hear my beeps when i get new mail for example), but windows cannot be moved, no keyboard commands work, nothing is responsive except the mouse moves around the screen and it appears like all app continue to run.
It requires a hard / physical reboot of the system to correct the issue. I find it mainly happens with Chrome and flash content opened, but cannot pinpoint the issue.
I have a strong feeling it has something to do with HD 3000 support. ?
Is this solved and I just don't see it?
Thank you,
Foxglove