Neo:6 no subwoofer??? help

[Gadget]

Just found the site and appears to be very helpful. Registered today but found no answers while searching this forum. Here's the deal:

Today I received my Polk PSW505 subwoofer and hooked it up. My System is as follows:
Sony STR-DE895
Klipsch RF-35's
Klipsch RC-35
Phillips DVP642 and a Toshiba 24" Flatscreen (unimportant but thought I would through it in anyway.)

Well I have been tinkering with all the settings trying to get it to my liking and I am very pleased with the sub so far, the sound is awesome and I have no complaints as of yet.
Here's my problem, I like the way the Neo:6 Music and Movies preset sound the best but when I switch to those, the sub doesnt play. If I go to A.F.D Auto, it works great but then the center channel does not play. Just the two fronts and the sub. Now, if I use some of the others such as the prologic presets, it just doesnt sound good and is really quiet.

What do I do to get the sub to work with Neo:6??? Please Help!
Thanks

 

[Gadget]

I seem to have figured out one of my problems... on the receiver when set to Neo:6 if the front speaker is set to large there will be no sub output. I had to set it to small and then the sub comes on.

Now another question, the sub hums when the receiver is turned OFF. What does this mean?

 

[JoeE SP9]

You may have a ground loop. Reverse the polarity of one AC plug. You may need to get a "cheater" 3 pin to 2 pin adaptor. Try reversing the polarity of the sub first.

 

[Gadget]

How do I reverse the polarity? =\ sorry semi-new

 

[Gadget]

It only hums when the receiver is turned off.. I can have the receiver on and on a device thats not even hooked up and its quiet, but as soon as the receiver turns off it hums.
Could it have anything to do with the cable direction? I am running a Monster THX ULTRA 1000 and it didnt come with a directional arrow on it. If I flip that around would that possibly fix it? or have nothing to do with it.