I was getting a similar problem over a period of 24 hrs or so. It seems there was a software glitch at their end which was responsible for physically creating work units and which has now been resolved.
In the mean time I started to use the new BOINC software. The first workunit required around six hours to complete and, to my surprise, there was no other workunit available for download so that I can continue by search for little green men.
I am now back to the classic version in my feeble attempts to try and reach the top 1000 in Greece (I started only in early May/2004 but I am one third of the way there).
Anthony.
  