I had always been running into problems with all custom roms giving me a 0x85010013 error when trying to sync with work.
Until now, the workaround was always, 'have somebody disable paranoia mode on the server' [paraphrasing], which can't happen in my case.
I happened across this post:
http://forum.xda-developers.com/showthread.php?t=485091
The tool, made for an i780, works on my HTC Touch Pro as well. 'everything's great now.
Posting, complete with my error code in case somebody else searches here and doesn't find a good answer. (no, I don't know what the rom tweaks).