Uploader not working

We have WordPress MU (I think 2.6 something) installed and the Uploader is not working…both flash and broswer. When I click the “Choose files to upload” nothing happens (Flash Mode). If I switch to Browser upload the broswer button works. I can add a file and click upload. But, I can only uplad small files. When I try uploading a file that is 56MB it waits for a second then refreshes the window (no files were uploaded). I’ve up the size limits to 3 gig of storage and 1.5 gig of upload size.

As for the flash…I tried to upload on Firefox for Mac, Safari for Mac, and Firefox for Windows. I even reinstalled the flash plug-ins.

Any thoughts/suggestions?