By the way, the backup does appear to work on Windows 2003 (I haven't tried a restore, but it does verify successfully), it just says it failed because of an unknown error.
I'm getting the same error message on Windows 2003. I do recall seeing a message telling me a patch was required when I installed either the remote agent or OFO. I have not yet been able to find the patch, however. Could someone please point me to it...