Just installed iOS 5 on my iPhone 4 and was looking forward to the flags functionality a lot but there's an issue.

I setup my zimbra mail using exchange on my iphone and everything syncs beautifully but the flags don't work.

The flags work if I use IMAP to set up, but it doesn't push or sync my calendars/contacts. Gmail works great with push and the flags work.

So if I set up my zimbra account on both IMAP and exchange (active sync) the IMAP shows flags but exchange doesn't.

Any ideas on how to get the flags enabled in my exchange setup?