2002 yukon denali transmission problem

I recently purchased a 02 denali loaded with only 44k when i picked it up. It now has 48k and i felt the transmission slip for the first time yesterday. I've driven it about 50 miles since the slip and it hasn't happened again. Has anyone else experienced this problem? I thought GMC was professional grade! Also i've noticed a whine has developed since i picked up the truck. Should've stuck with the original plan and bought a sequoyia, DAMN!

Sorry to bitch, i'm just kind of irrated with american quality.

YES I feel the same way,I have a 2000 YUKON DENALI 5.7L I am not sure what transmission I have, the 350 engine does have balls, when you step on the gas normal drive the transmission shifts ok but when I step hard on the gas the transmission does slip it lags to enter gears it sucks, ONE OF THE BEST THING TO DO IS TO GET A SUPERCHIPS TUNER PART#2715 WILL MAKE YOUR TRANSMISSION LAST LONGER=more life

In addition, part number 2715 provides the ability to:
Adjust Shift Points
Adjust Shift Firmness
Eliminate Speed Limiter
Recalibrate Speedometer for Larger Tire Sizes
Recalibrate Speedometer for Gear Changes
Adjust Rev Limits
Choose from Three Available Performance Settings

or try an INTERCEPTOR Adjust Shift Firmness CLICK >>>>INTERCEPTOR (http://www.autotransinc.com/intercept.htm)

SUPERCHIPS $200-$350
INTERCEPTOR $130
THESE TWO OPTIONS ARE BETTER THEN WASTING $1,000-$1,500 ON TRANSMISSION REBUILT