Problem with Tritton AX pro and Asus P5Q Pro on board sound

Hey there, can anybody help or give me some ideas to try?

My old headset packed up so i decided to invest in a set of tritton AXpro's. I connected the analogue jacks to the correct connectors on the back of my P5Q motherboard, went into sound settings (win7) and changed to 5.1 sound. Sounds was stereo only although mic worked well. I wasnt able to change the sound to 5.1 in settings.

Solution: I downloaded the latest drivers from asus (released in 2009) for the on board sound.
I did seem to then be able to change the sound to 5.1 in settings and after removeing and reconnecting the jacks all the channels now work! Hurrah!!!!!

However, I still have 2 very annoying issues. With the new drivers my mic now feeds back through the headphones which I find really annoying. I know this is a personal preferance thing but all reviews say that these headphones do NOT do this so I fear it is an issue perhaps linked to my problem 2: TERRIBLE HISS!!!!! By turning everything up to full and my headphones down I can reduce it a little but the sound is still terrible.
...I dont know what to do next :S and would really appreciate some suggestions.

Thanks
Firefly