In the process of moving house and a handy Three movile broadband dongle is a great in-between when waiting for a new internet connection to be installed in the new place.
So of course the first thing I asked at the shop before I brought it was 'does it work with Linux?' and of course the answer was 'No'. Anyway I quickly got on my phone and did a quick search of the Ubuntu forums to find a few threads claiming it can be solved (this one in particular is very comprehensive: http://ubuntuforums.org/showthread.php?t=1466490).
When attempting to log-in to a Drupal website I encountered this error, and couldn't log-in. Bit of a headache, in my case I solved the problem by loading up phpmyadmin, going into the variables table and deleting 'cron_last' & 'cron_semaphore'. I then went into the system table and disabled dblog, poormanscron, search and update modules.
This has solved the problem, I'm not exatly sure what the problem is though. This article on d.o indicates it's to do with performance: http://drupal.org/node/259580