Weird Mail.app bug

Hi guys, I have a weird problem with my mail.app in so much as every other time it checks my mail, the progress bar shows a few messages comming in, along with the size etc but they never appear in my inbox.

Thsi started out a month ago as alwways 2 messages, but it's getting bigger now and I am currently up to 8.

This happens all day and they never show.

I still receive emails OK and I have no junk filter (either in mail.app or with my hosts)

Any idea what this is or how I can get these ghostly emails?

 

No it's POP and I only ever check email on this computer, never my iphone.