When running nouveau on my board, I get a DMA queue hang. nv handles this just fine.
My board is a Geforce 7300 GT and I'm using a flat panel on DVI.
Created attachment 13494 [details]
I can also add that restarting X after this hang crashes immediately with another "DMA queue hanged". Starting X yet another time gets things going again though.
Please, re-test, and re-open if the problem still exists. A lot has changed in over 1.5 years. Note, that KMS is the future. Actually, I'm not sure if xvidtune is even applicable in KMS world.