The new kernel installed 8 May hasn't fixed the problem for me.
uname -a Linux xxxxxxxxxxxxxxxxxxxxxxx 3.8.0-20-generic #31-Ubuntu SMP Mon May 6 17:03:32 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
The new kernel installed 8 May hasn't fixed the problem for me.
uname -a xxxxxxxx 3.8.0-20-generic #31-Ubuntu SMP Mon May 6 17:03:32 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
Linux xxxxxxxxxxxxxxx