Reply to Realtek Line-In Problem - Adobe Audition - XP

Recently I just got a Dell Inspiron Mini w/XP and Realtek audio driver. I figured it would be a great little lappie to record mixes with. So, toevening I went to plug my mixer (Vestax PMC-50Pro3) into the microphone Line-In port. I've got a good Monster Cable RCA to 1/8th jack I've been using in the past, worked great on my old laptop (which is dead now). All I had to do was plug it in, select Line-In, fire up Audition, press record, and spin away. Easy.

Now with this new Realtek Audio Driver, when I plug my RCA to 1/8th into the microphone jack and select Line-In, it says, "This Device Type Not Supported!" Damn, I thought technology was supposed to make things easier. Ive tried fiddling with the Mic Volume option, the Stereo Mix option, and nothing works. Now I'm here, it's 12:00am, and I have not a damn thing to show for it. I'd really like any advice or remedies you can offer me, if you're near here I'd even buy you a beer or two. Pretty frustrated right now at the whole thing. I was supposed to have this recorded toevening .

Many thanks to anyone who can shed light on this, and I apologize in advance for any dumb/obvious/novice questions.