Hi all... First time post here... tried searching through the archives, but have leftover questions. Sorry for the detail here, but it helps to have all the info.

Current setup:

*DJ Scratch Mixer with RCA outs & 2 balanced 1/4 inch outs
*Edirol UA-20 USB device
*PC with an integrated soundcard (which has 1/4 inch inputs and RCA outs)
*Recording live mixes, making loops, and creating new tracks primarily with Sonar 2XL
*One pair of speakers with a sub that all connects via a male 1/8 inch jack (came with my Dell, but sound kick-ass)

The goals:

To be able to use my DJ mixer for casual listening (read: don't want to go into Sonar and turn on input monitoring).
To hear the sound my computer makes through the speakers.
To do all this while avoiding the following problems.

The problems:

I've set up and torn down my gear 1,000 times, and wind up with these issues.

If I split the inputs running to the speakers (using a female 1/8 to 2 female 1/8 jacks), and connect both the computer and the mixer, I get a high pitch squeal when I try to record (is this a feedback loop?) Also, there seems to be a quality of sound lost when they are hooked up in this way.

Alternatively, I've tried running the computer back through my DJ mixer on a line input, and then run the mixer output to the speakers. The side effect of this situation is that I can't multitrack anymore in Sonar (because the only way to cue a track on my computer is to play it through the mixer, which makes a loop back in to the computer!!! ARRRGGGHHH!!)

When I have tried to run all of the sound output out of the Edirol into the speakers, I have no way of listening to the DJ mixer without input monitoring.

Possible solutions:

A Mixing board? I'm not sure how this will help matters, or where in the chain it would go.

A second set speakers. Would definitely solve it, but I feel like it's cheating! Hasn't this problem been dealt with before?

Am I making this much harder than it is? If you've gotten this far down, you are brave! Thanks for your help...