I had the same problem and checked every conceivable log and even did profiler traces to no avail.

I finally stumbled onto a solution that at least worked for me. It had to do with enabling AWE (Address Windowing Extensions allow 32-bit operating systems to access large amounts of memory. One first has to enable the lock pages in memory option. See links below. Hope this helps.

http://msdn2.microsoft.com/en-US/library/ms190730.aspx

http://msdn.microsoft.com/en-us/library/ms190673%28SQL.90%29.aspx