Dreanmachine

I just purchased a new HP PC with Windows Vista. I plugged my wireless
headphones into the primary (front) channel in the back of the PC, and then
external speakers into the secondary (rear) speaker jack. I have the Reaktek
HD manger set up for quad speakers. The front and rear speakers tested out
ok in Reaktek (I heard all sounds in L/R for front and rear speakers).
However, when I play music, it only comes through the wireless headphones,
but nothing out of the rear configured speakers. What is up with this? Do I
need to get an updated Vista driver for Reaktek? Or is something else amiss?
Any help would be appreciated. Thanks in advance!