You mention this started after you upgraded to kernel 2.6.28-9.29. Does the issue go away if you downgrade (you can test by just booting an earlier kernel)?
Actually, my best guess is that this is related to the libdrm 2.4.5 update, which happened on the 9th. Do the issues go away if you downgrade that to 2.4.3?
(Fwiw, I've seen these messages myself, thanks for chasing down what triggers them.)
Florent,
You mention this started after you upgraded to kernel 2.6.28-9.29. Does the issue go away if you downgrade (you can test by just booting an earlier kernel)?
Actually, my best guess is that this is related to the libdrm 2.4.5 update, which happened on the 9th. Do the issues go away if you downgrade that to 2.4.3?
(Fwiw, I've seen these messages myself, thanks for chasing down what triggers them.)