So just to close this thread out... I gave up on linked server under the premise that SSIS would probably be a better way to go about doing what i need to do. So long as i manually build the query i can get mappings to set column types etc just fine. Go figure.
Thanks for posting back. Don't think it's you - their drivers really are flaky. I've only had to use them on rare occasions and that was bad enough. You have my sympathies.