What does the manual say?

The manual contradicts itself. It really isn't clear as to what you should use when you want to combination cook ( microwave and convection ) I guess the best is to trial and error, however, I don't want to mess up the unit! I'm hoping that someone is familiar with how to cook with this microwave/convection combination.

Find out who the manufacturer is and call them and ask to talk to a tech. You really don't want to experiment - you might damage the unit.

I have 67909 model and the manual (pg 9) shows that you need to use the turntable for all modes and the metal rack for convection & combination only. In combination (which I haven't done yet) you need the turntable, rack and microwave safe/oven safe cookware (e.g. corning ware, pyrex). In convection only you can use metal. Hope this helps...and yes, you really had to flip around the manual to confirm this!

I have a ka convection microwave that appears to have similar racks. It does not have microwave and convection, but does have microwave and broiler at same time. It says you can use metal pans, it has a metal trey anyway. With microwave only, it even says you can use aluminum foil! BUT you shouldn't allow the foil or any other metal object to touch the walls.