There have been some issues found with the fronts that were solved by loosening the regulator and retightening it. Seems that it was binding. However most experience problems with the rear regulators breaking.
Goldfinger, you should post in each thread that you are talking about a '99 Park Avenue, not the Bonneville in your signature. While there are similarities between cars, the differences will only allow us to take you so far.
well I took the front door panel off ( real easy too ) and lubed the tracks, the motor looks like a gear drive motor not a cable like the link above but after lubing everything it seems real good now ( fingers crossed ) I will keep you posted !
My girlfriend'* 95' Intrepid had the same problem. Still does. Why? Because her door frame was bent out near the tip and leaking air/water. I took my knee to the bottom of the door and bent the top inwards, now her beater doesn't leak air or water, but the windows **** me off after being in my 2 second bonneville.