Merging email problem

I use Mobile Me to connect my MacBook, iPhone and iPad. On the iPad occasionally two emails will merge into one in the inbox. There will be the sender name and email subject but the body of someone else's email. So I cannot read the email from the sender I can see unless I go to my MacBook and then the 2 emails are separate as they should be.
I have spent hours on this with MobileMe chat (ugh) and in the apple store.

Has anyone experienced this or does anyone have any idea? Maybe deleting MobileMe from all three devices and reinstalling would work?

Thanks in advance