Iphone and IMAP

[#1]

I've been using IMAP on my iphone, a laptop and a PC with no problems for a while now.
However I decided to create some folders in my mailbox on the PC, and then move the hundreds of mail from the inbox into the folders.
When I check my mail on the i-phone, it knows the folders are there, creates them on the phone, but when I look into one of the folders, it seems some mail is not showing.
If I look on the PC or webmail, they're there ok.  They also seem to mail from just one person too (although I can't prove that yet).
If I use the PC and move an e-mail that isn't visible on the iphone, from the folder into the main inbox, I can then see it on the i-phone.  I can then use the iphone to move it to the folder and it shows in the folder ok.
I've tried deleting the mailbox on the phone and recreating it, but same thing happens.
Anyone seen anything like this before?
Regards
Carl

[#2]

Perhaps in order to save memory on the phone it's only loading the headers for the most recent emails (which is why they show in the inbox when moved)? Just wondering. If you order by date and try to scroll past the oldest email does the phone attempt to download the rest?

[#3]

I don't think it's a data thing as I can see mail both before and after where I'd expect to see the mail i'm missing.
It's definately an odd one, and I may end up moving everything back to the main inbox.

[#4]

You might try renaming the folder.  Some i-map folders are hidden by some i-map clients when they have particular names.