[Lizard]

If none of the suggestions above seem to help, please feel free to contact our Support Ninjas. They should be able to work with you one-on-one to figure out what's going wrong.

It'd probably be most helpful to email them (omnifocus@omnigroup.com) a sample taken while OmniFocus is being slow. To do this, open Activity Monitor and double click on OmniFocus in the list of processes. In the new window that opens, click the sample button. Save the sample as a text file, and attach it your email.