Gears & Axles - anybody having noise problems with s60 4.30 gears?

Had my first set start making noise, unbearable noise after about 6-8 months. They paid to have them replaced. Now after breaking them in and putting about 20 1/4 mile passes on them, they sound the same as the old ones. WTF? Car only has 430 rwhp and goes 1.5-1.6 60ft times. Anybody else have noise issues with that ratio gear?

Ryan

Also, this is a 6spd car, 3900# with me in it, with the s-trac differential, on 26" et drags. Thanks