ac97 no line in KN8 amd 3200

First of all my specs are:

motherboard: KN8 platinum
processor: amd athlon 3200
memory: 3 gb ddr 400
hdd: IDE 120 gb 7200 rpm
graphics: nvidia 7600 gs

the audio chip in my motherboard is ac97. Yesterday I installed final ipc 10.5.6 ppf5 with no problems, and graphics, LAN, sound, graphics are working, but I noticed I can't get input sound to work. I tried connecting a mini jack input known to work into any of the connectors in my motherboard and I get no sound, even though all sound is working, it's just the line in input that is not working. I checked all options in system preferences -> sound->input, and selected Line in, made sure mute was unchecked. Tried this with a ideneb 10.5.6 install, and got same results. The driver I choose during installation process is AC97.

Any Ideas? this it not a big issue, but I use the Line in a lot. I also have a X-FI sound card installed in this pc, correct me if i am wrong but there is no support at all for this card right?

Any ideas are wellcome. Thanks.