Hello, I made some progress. After switching update to sequential boot I saw the following exception: machine check in kernel mode caused by (from SRR1=49030): Transfer error ack signal oops: machine check, sig: 7 [#1] the top entry of the call trace is: gem_ioctl+0x60/0x94 [sungem] But this seems really odd to me. If the error is in the kernel module, why does it still occur after switching back to the old kernel?