WordPress MU

When i upload a photo with flash it shows it uploading to 100% then it says
(File is empty. Please upload something more substantial.)
When uploading with browser uploader it says error uploading media file, what the hell gives, im using latest MU 2.8.4 and latest Everything, just started across all blogs this morning?

Ive installed no new plugins, no updated plugins, no php or added or changed anything at all, what gives now?????????

Frustrated as hell!

If nothing has changed in your MU install, then you need to look at the server config. Bad mime type configuration on the server?

kgraeme, you hit the nail on the head, thanks so much for your help, bad mime type configuration is what it was!!!!