[Lizard]

Sounds like it certainly could be a problem with OmniPlan itself. Would it be possible to send your file to us? Choose "Send Feedback" from the Help menu, and you'll have an option to attach a sanitized version of your file. (Task & resource names will be changed, notes will be replaced with x's, etc.) Send that email to us (omniplan@omnigroup.com) and one of our Support Ninjas will figure out what the problem is.