So this is what has caused it? ....?
I have an issue now where if my SD card is present I receive no SMS/MMS/voicemail notifications.... I use AT&T Tilt. AT&T said it has to be a card issue. HTC said it has to be a card issue. But I still have a subset of the symptoms when the card is ejected...
My issues are similar. Outlook has new account called System. I can add new accounts but they only seem to work for about a week and then feeze. I am only able to access the setup folder for messaging when the SD card is ejected. HTC said there is nothing in the messaging configuration which would depend upon the SD card. I think this is bogus as there is an option to save attachments to card rather than main memory. I'm guessing now that My Phone has edited my system registry and changed the behaviour. It could be that the SD card is defective in some way and that the issues are coincidental with My Phone install but unrelated.
A can of worms....