OWA Won't Upload Attachments

[Michael Catalano]

I'm running Backoffice SBS 4.5 with Exch5.5 + OWA, IIS4, and Proxy 2.0. We removed proxy, afterwhich OWA appeared to work fine except that you couldn't upload attachments. They start to upload, but they never complete. No error message is displayed. I found a few technet articles about that, but none seemed to apply to my situation. Permissions are set correctly on the Exch virtual root in IIS and on the .\exchsrvr\webdata directory.

We finally tried removing OWA completely then rerunning the IIS install followed by SP6a. Then we reinstalled OWA and ran Exch 5.5 SP4. The same things happening, attachments start to upload, but nothing happens. Any ideas?