Eventually got the downloads working by deleting one of the apps (it was the update I was trying to install) which seemed to sort it for the others.
But today another problem, the phone won't sync to my emails! Sigh. It doesn't even tell me that there is a problem, it's just that nothing happens, at all. It was fine yesterday, but today, no little round sync symbol appears, no new emails, nothing, nada, zilch.
I've tried turning the phone off and on again and removing the battery, turning wifi and 3g etc on and off again, clicked refresh dozens of times, but nothing seems to get the bugger to start syncing.
I have no idea what to do now. Should I just reinstall the upgrade and start over again?