headset/micro problem

hey,
i have a problem with my headset and micro - since i ve installed "Sony Ericsson PC Suite" for my new phone i can hear the input of the micro but the normal video/gamingsound as well... so if i shout -> i hear me shouting...

i didnt change any connectors so i have no clue how to solve this problem ;(

can anybody help me

(win xp pro, amd 3500+, geforce 6800gt, speedlink medusa 5.1, and a 30 euro soundcard from audigy (sb live 900 driver or something)