Mock Operation Dispatch Setting

Hi,

I'm brand new to soapUI and trying to get the MockService set up. Things seem to work ok, but the default Dispatch type for an operation is "Sequence" and I am unable to change it. I click on the drop-down, it opens up and I can select something else, (e.g., Query_Match), but the UI does not update and when the drop-down closes, it still has Sequence selected. I also downloaded the PRO trial version to see if this was a limitation of the free version, but I get the same results. I've tried deleting the operation and re-creating it, but with no luck. Any suggestions?

I'm running 3.6.1 on a Mac.

Thanks,
Rob