I'm having an issue with scheduled workflows in my account. Intermittently over the past few months scheduled workflows running on different record types (Sales Orders, Item Fulfillments, Custom Records) wont initiate when they are scheduled. I've been on the phone with NetSuite customer support many times with no progress. The only thing that helps sometimes in clearing the workflow instance history. Any other suggestions? Any ideas that might help?

Check that the records to be triggered aren't in a workflow state of the same workflow.