hey Andre, nice seeing you eyeing around in the forums. You sound a little bit annoyed though :-( Come on, don't despair, you guys are doing a great job! Thanks for the brainstorming link, I voted in there. I find the separate app a good idea, reminds me of the setup I had with Android: the "Exchange" account stays free for a business account to be configured and the GSync (or whatever you'd like to call it) can be used to sync to my personal calendar. So I can have business and private live nicely separated but both kept in sync. Anyway...

@all didnt have to file a bug, bug has already been filed quite some time ago by other members. Obviously it's not bound to MfE-Google, happens with MfE-Exchange 2003 as well and Exchange 2003 should be mostly supported, I thought.

@balleyne If I were you I'd clean out my device and freshly start over. Try this to get around a reflash: delete the MfE configuration and delete the calendar MfE syncs into as well and then reconfigure MfE. In case you dont know where to fiddle around to get this done:
In Settings chose MfE, hit the Settings button and then hit the Delete button. This will remove the MfE account, hope you still have your login details ;-) As for the calendar, before you re-setup MfE, remove the calendar MfE synced into. Open Calendar, get the menu, chose Settings, then chose Edit calendars (1/2/3/x visible) where you will be presented with a list of all calendars on your N900. If you synced into the default N900 one, tap it, chose Delete which will throw security questions at you. Answer then to get the calendar purged since it cannot be fully deleted. If you created a separate calendar and did not sync into the N900 default one, delete that one. It will be marked with "synchronized". This as well will throw security warning at you, answer accordingly to get the calendar removed. Once done, recreate the MfE account. Now, in the final step before the initial synchronisation, set the calendar sync to create a new calendar and not to sync into the N900 default calendar. There is a button in the calendar sync details which lets you change the calendar and/or let the sync create a new one.
Hopefully this will sort things out or at least keep you up to date without any worries for a couple days and/or weeks ;-)