Internal Server Error

I have 3 machines running Einstein @home. One of them is now out of work, with 3 processes showing a status of "Ready to Report". When BOINC tries network communications it gets an error.

Any ideas what this means and how I can get around it?

Thanks.

8/9/2010 8:00:56 PM Einstein@Home Sending scheduler request: To fetch work.
8/9/2010 8:00:56 PM Einstein@Home Reporting 3 completed tasks, requesting new tasks for GPU
8/9/2010 8:01:01 PM Einstein@Home Scheduler request failed: HTTP internal server error
8/9/2010 8:01:06 PM Einstein@Home Sending scheduler request: To report completed tasks.
8/9/2010 8:01:06 PM Einstein@Home Reporting 3 completed tasks, requesting new tasks for CPU and GPU
8/9/2010 8:01:11 PM Einstein@Home Scheduler request failed: HTTP internal server error