>Another curious aspect of this that I just discovered is that, when you trace through the code in the debugger, the error does not occur. If I simply run the code from within the IDE, the error still occurs.
>
>I don't know if is a timing issue (i.e. tracing through the code happens much more slowly and may give some background process more time to complete) or if there is a condition that is not occurring in trace mode.

Do you've a timer in your application that could somehow interfere?