5.1 speakers on Audigy 2 problem???

[Agent.M]

Heys guys I just bought the logitech z5300 5.1 system and Im connecting it to a audigy 2 sound card, but for some reason when I go to calibrate the system Im only hearing sound out of the front R/L speakers, and nothing out of the center or rear R/L ,also for some reason when I try and run a diagnostics test i cant cause the button to click on too start the test doesnt show up, I have 5.1 selected in both the control panel and the creative console and have updated my drivers and tryed uninstall reinstall as well. Any one have any ideas?