Has occured more than a few times today. Appears when I select a message - hit reply all - and then begin typing... I get a few words in and than WHAM.... it hangs... w/out any response... but outlook continues to use 35 - 50% CPU. I end up killing the process and restarting outlook... any clues as to how to diagnose the issue? Event viewer lists a few checkpoint rollbacks on some .psts and indexer reconciliations throughout the day.