Okay it looks like 7.1 is out.

How about 5.1 surround through a 7.1 system if the DVD output is only 5.1? Does it make sense to feed the right surround signal from the 990 through the right middle and rear surround speakers and the left surround signal through the middle and rear speakers? Would a Y-connector make sense for this? I bought the extra speakers and amp because I had the money at the time and I would hate to have them just sit there.

Thanks to all for your help.