file uploads fail with no message

I am trying to upload a file and either (1) the upload just hangs, apparently working, but 4 hours later, nothing has changed or (2) I get the messages "Sending request to blancmange PBwiki", "Tranfering ...", then no message, no file in the listing of files, and no reduction in storage space. It's a 70 MB file, called "farina-latest.tgz". I uploaded some little image files with no problem in a free PBwiki, then I paid $100 for the year, intending to use this wiki to collaborate with colleagues in various locations. The wiki part is working well, but I have to be able to exchange files, too. I haven't even tried to upload the 430 MB data file!
This doesn't sound like a case of questionable content--unless you're unzipping and untarring and scanning all the Java source code in this file, and finding something random in an object or method name.