What does it mean when the electronic stability program light stays lit on my Audi A4 2002?

I found someone who experienced the same issue here. My '04 S4 is doing the same thing and I'll probably reference the solution at the following URL when I get it checked out:

http://www.audiforum.ca/Audi-a4/1318-anyone-experienced-broken-esp.html

Here's the text from the user's response at www.audiforum.ca:

"Re: Anyone Experienced a Broken ESP? I had this problem with my 2005 A4 Avant but I figured it was normal and never got it seen to. One day I noticed after parking the car and walking away that the break lights were on. I took it to the dealer (still under warranty) and apparantly my break switch was a bit flaky (this explained why sometimes when I pressed the lock button on the key chain sometimes the car did not beep, since it thought the break was being applied). Once the break switch (sorry not sure of the technical name) was replaced my intermitent ESP problem never came back.

"

-Chris