Kevin, thanks for that update. I will be starting on a new site next week in CF9 and will report if this null null error shows up.
Haven't migrated any of my old sites (several CF7s, a few CF8s) to CF9 yet, but may be doing so once we get a picture of stability issues, etc. I find that my CF8 sites are are bit more likely to get timeout, connection errors, etc., even with the "Maintain connections" uncheck fix in place.
-James