We have a bug in our application that does not occur every time and therefore we don\'t know its \"logic\". I don\'t even get it reproduced in 100 times today.
Disclaime
Read the stack trace carefully and try to guess what could be happened; then try to trace\log every line of code that potentially can cause trouble.
Keep your focus on disposing resources; many sneaky sporadical bugs i found were related to close\dispose things :).