Problem with gmail and iphone

I’m setting up my daughter’s new iphone with gmail using google sync.

Her address book and calender work perfectly.

But her unread messages show up in her inbox on the iphone. Read messages aren’t displayed on the iphone – only on the web.

Any suggestions?

If so, please email me at bsabet at gmail dot com

or you can @bijan me on twitter

or use tumblr reply

Thanks! I’ll make sure to update this post with the fix. 

(btw, I do have imap enabled) 

7/24/11: Update: Thanks to Javier, problem solved !