I saw anidel's post about syncing the n900 with Google mail, calendar, and contacts in the maemo.org news feed, and also posted a comment there (pending moderation), but please vote for this bug in the meantime...

In short, MfE configuration settings are 'forgotten' after some number of syncs, calendar stops syncing, etc... until you realize the issue, and toggle calendar syncing on again.

https://bugs.maemo.org/show_bug.cgi?id=11557

Thanks.