garymomo, chcw - tried both of those things.
jakirkhan - I followed your procedures, which is basically the same thing garymomo and chcw are saying. This half-worked. It would download to the new ost file completely, but would not add new mail after the download and would give me the same error when I restarted outlook. If I recreated the ost file again, same thing, but would cache the new mail missed after the previous cash, thus growing the ost file each time.
In fact I did fix it. I ended up running the scanpst.exe after all. I was cautious about running this because of the KB link, but it worked. I'd like to award some points for taking the time, but they don't have a category for that!