mc420

I have a 03 wrx, and lately i have been hearing a click sound from the front of my car. The sound only happens when i let the clucth out in first geer, or when i hammer the throttle and let off abruptly and then hammer it again. It sounds as if the front diff. is engaging like it should, but there is play or something in it...i have 7k left on warranty, but if this is fairly normal i won't bother with it. I had the clutch replaced at about 40k with an Exedy organic clutch and Exedy lightweight flywheel...the new "click" sound is very new, and only happens primarely when first geer engages, after that it is gone. No other noises at all. Not even while cornering. Any help is appreciated. I also have KYB adjustable shocks, and Helix lowering springs. Thanks, Matt