OK... so the wiki problem was not due to database issues. I've checked the logs and all was good. It seems that someone deliberately wiped out all of the wiki data (except for a doc or two that I found).
I was able to restore all of the docs, minus two that Omicron had submitted recently (after my last good backup)... but between him and I we had copies of the two missing docs. So everything is back to normal (zero docs lost).
I will be locking down the wiki, until I can figure out a safe way of allowing everyone to edit it, and still feel comfortable that someone won't destroy it. I know this defeats the general purpose of a wiki... allowing all to have access to contribute, but I think there are few people now who contribute docs, and mostly people just refer to it.
hopefully this is just a temporary solution... if anyone has any thoughts or feedback, I would love to hear it.
thanks