I too am having occasional freezes.
I have upgraded from a very stable system running a Crucial C300 128G SSD to a SanDisk Extreme 240G - basically for the extra space.
After, and during, a fresh install of Windows 7 64bit I had a number of freezes where I needed to use the big red button to close the system.
If I drop back to the old Windows install on the Crucial, everything works just fine.
I have also had an interesting problem with the instalation of one of the drivers, which I will raise as a separate post.
Motherboard - Gigabyte GA-X58A-UD3R Rev 1
Memory - Corsair Vengeance 12GB (3x4GB) DDR3 PC3-12800C9 1600MHz
Graphics Card - nVidia GTX 460
System Drive - SanDisk Extreme 240G - Ver R201
Storage 1T Raid 1 Array, 2T Raid 1 Array
Spare - Crucial C300 128G SSD (Currently contains old Windows system)
All in a Fractal Design R3 Case with copious airflow
BIOS, Firmware and drivers all at manufacturers latest.
NB - No overclocking