Didn't know there was a MM account that resides on the phone. Where is it?
On your iPhone do the following:
Go to Settings
Touch "Mail, Contacts, Calendars" where you should see at the top of the screen a mini panel titled "Accounts"
Touch the Mobile Me account you created (you did create one, no?) which will have a subtitle "Mail, Contacts, Calendars", and then touch the big red button that says "Delete Account"
That's it, you're done, no more MobileMe account on your iPhone.
To then re-create your Mobile Me account on the iPhone it is back to Settings (on the iPhone).
Touch "Mail, Contacts, Calendars",
Touch "Add Account"
Touch "mobileme" and fill in your account details.
That will put up a fresh setting of MobileMe on the iPhone.
Hot tip - fiddle around with MobileMe settings on your Mac or PC first, get the sync/push working between your desktop and the web app first. Only when all that is working okay should you even consider setting up MobileMe on the iPhone. Also, if you change anything, absolutely anything at all in MobileMe (i.e. adding another Mac, removing one etc ....) then you need to delete and recreate your MobileMe account on the iPhone - if you don't then Push to the iPhone will not work. I have been able to re-create that 100% on demand, it is a bijoux bug.
I'm not around for a couple of weeks now, so good luck with your stuff
Edit:
There is a comprehensive guide to setting up
Mobile Me on the Mac and iPhone here. It is no accident that they tell you to
set up the iPhone last (although that is not emphasised sufficiently, in my opinion).
But one thing is for certain - very many problems are caused by people not following these guides
to the letter. I suspect that, given you have said you have a similar environment to me, you've possibly not worked through the set-up correctly. No harm done, probably
, its easy enough to go through it all again. It is frustrating as hell to see it not work as you rightly said. But it can be made to work..
Like I said earlier - its pretty much a case of RTFM, then RTFM again, and follow it to the letter. If it still does not work there is most likely something non-vanilla about your installation and you need to find out what that is. In my case it was a pre-existing set of "dotmac" .plists that needed deleting.
This stuff does work "out of the box" - just not always after a few months of a user having their hands on it