I'm getting some AssertionFailures (collection not processed by flush) that I can't seem to understand the source of. Before I go trying to produce a test case, could someone enlighten me about:

1) What exactly is unsafe use of the session.
2) What sort of things could cause a collection not processed by flush AssertionFailure.

It would help me to try and frame the problem in the context of my application. Right now I know something is going wrong, but I have no idea what or why, nor where to start looking.

1) Not thread safe
2) Don't use session if you have had an exception.
3) Always use approrpiate Transaction management code idiom(s).

There are ways around the above items but apply as a general guideline.