Logged In: YES 
user_id=947543

We changed the backend from anydbm to bsddb and the 
problem went away, so we appear to be in good shape now. 
Thanks just the same!

To answer your question, there is a very good chance 
someone else was using the tracker at the time the issue 
occured. 

(And sorry if I should have used the mail list for this sort of 
thing...)

Mike