Daniel
I have the same problem. My issue is not yet resolved , but you may have more luck.
Have a look at the following and see if one of the solutions helps you.
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=124329
It may be an acpi issue, but you will need to provide the trace log and your machine info
before someone will be able to help you further.
Steve
