Comment 12 for bug 296663

If you could also test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine this issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

If the issue remains with the upstream kernel, please be sure to also run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux-image-2.6.28-11-generic <bug #>

Thanks in advance.