Asking the same question on multiple forums without waiting on an answer is the new these days, not x-linking on same so people know what's been discussed elsewhere is another new, but think you do best by returning there and see what comes out: http://milkyway.cs.rpi.edu/milkyway/forum_thread.php?id=4156 where a reply said your problem per observation is resolved as the reply is "Whatever it was it seems to be working as you have a bunch of new tasks and even some valid ones now."

In majority its a Linux issue where BOINC starts before the GPU drivers have fully loaded. Use a sleep function to delay BOINC from starting, courtesy of the Debian package maintainer. Windows has a similar function "Automatic (Delayed Start)", which you can control somewhere under the services applet, were it not that BOINC cant be run as a service under Windows if you want to do GPU computing.