Same issue I think, except mine works on iPhone 4 and used to work on iPad 2 but since 25th May it just doesn't update my mail anymore. No errors coming up and weirdly I still seem able to compose and send emails from the iPad, but it will not download any new messages from any folders. Yet everything works perfectly well on the iPhone, all settings are identical.
Any thoughts would be great fully received! Cheers in advance!