I have updated the system about a month ago and the problem is gone since then. Here is the information on kernel and distribution versions with the most recent updates installed:
# uname -a
Linux mtr980 3.2.0-31-generic #50-Ubuntu SMP Fri Sep 7 16:16:45 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
I have updated the system about a month ago and the problem is gone since then. Here is the information on kernel and distribution versions with the most recent updates installed:
# uname -a
Linux mtr980 3.2.0-31-generic #50-Ubuntu SMP Fri Sep 7 16:16:45 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
# cat /etc/lsb-release RELEASE= 12.04 CODENAME= precise DESCRIPTION= "Ubuntu 12.04.1 LTS"
DISTRIB_ID=Ubuntu
DISTRIB_
DISTRIB_
DISTRIB_