12.04.3 and 13.04 both use the 3.8 kernel. There may be a regression in the 3.8.13.5 kernel. Do you happen to know the kernel version you were running in 13.04? Can you run uname -a on the 13.04 system?
Also, it would be helpful to test a few kernel to confirm if this is a regression or not. Can you test the following kernels on the 12.04.3 system:
12.04.3 and 13.04 both use the 3.8 kernel. There may be a regression in the 3.8.13.5 kernel. Do you happen to know the kernel version you were running in 13.04? Can you run uname -a on the 13.04 system?
Also, it would be helpful to test a few kernel to confirm if this is a regression or not. Can you test the following kernels on the 12.04.3 system:
3.8.13.2: http:// kernel. ubuntu. com/~kernel- ppa/mainline/ v3.8.13. 2-raring/ kernel. ubuntu. com/~kernel- ppa/mainline/ v3.8.13. 3-raring/ kernel. ubuntu. com/~kernel- ppa/mainline/ v3.8.13. 4-raring/ kernel. ubuntu. com/~kernel- ppa/mainline/ v3.8.13. 5-raring/
3.8.13.3: http://
3.8.13.4: http://
3.8.13.5: http://
You don't have to test every kernel, just up until the first kernel that exhibits the bug.