Error trying to add op to new sub-ass'y (Vantage 8.0.409c)

If we add a new subassembly to a job and then try to drag and drop a new operation or resource group onto that subassembly the new op doesn't appear and, on trying to save, we get an error message that says "Index -1 is either negative or above rows count." Often, the job entry screen won't allow us to exit when this happens and we have to shut down teh session through task manager. Anyone know what this error means and what to do when/if it occurs?

It looks like saving between steps avoids the error (I wasn't able to recreate it). Is it possible to add ops to a new subassembly without saving?

Also, the single biggest complaint from the users after going from 6.10 to 8.03 has been many more keystrokes/mouseclicks to accomplish the same tasks. Is this a common issue or are there simplifications that we just need to find?