I'm not running into the same issues here on the same file, so most likely there is something else at play here. The first thing I would suggest would be to disable threading (File -> Settings -> Expert -> Number of Helper Threads) and see if that does anything.
After that, I would recommend filing a support ticket (
http://support.ootpdevelopments.com/...Tickets/Submit) as the next issues would involve specific troubleshooting on your machine or the save files.