OK finally narrowed it down :
~$ uname -a
Linux Aspire-5670 2.6.32-19-generic #28-Ubuntu SMP Wed Mar 31 17:46:20 UTC 2010 i686 GNU/Linux
In kernel 32-18 the problem starts
***************************
Last good kernel is
~$ uname -a
Linux Aspire-5670 2.6.32-18-generic #27-Ubuntu SMP Fri Mar 26 19:51:10 UTC 2010 i686 GNU/Linux
OK finally narrowed it down :
~$ uname -a
Linux Aspire-5670 2.6.32-19-generic #28-Ubuntu SMP Wed Mar 31 17:46:20 UTC 2010 i686 GNU/Linux
In kernel 32-18 the problem starts
******* ******* ******* ******
Last good kernel is
~$ uname -a
Linux Aspire-5670 2.6.32-18-generic #27-Ubuntu SMP Fri Mar 26 19:51:10 UTC 2010 i686 GNU/Linux
The fix for Bug #507148 caused this problem