Korg made the strange decision to have the lights for toggle mode pads switched to 'on' all the time, so after finding the padKontrol sysex information on this forum and reading about active mode, I figured I could sort out a program that would make the thing behave how I wanted it to.
So, here's what I've done so far - FarmPad takes over the padKontrol and turns every pad and switch on it in to a toggle. The toggle has it's light off when switched off, and the light comes on when it's switched on.
The other controls still work, and I've made the rotary encoder in to a MIDI control too.

This works for turning loops on and off in Ableton too - set the loop's trigger mode to 'gate' then assign a toggle to it.
It's gig-tested, but only on a Macbook Pro, 10.4.9 - please let me know if you get it working on your machine, and also if you have any problems.
I'm going to get round to doing a Windows version, but I'd like to get the planned features sorted out before I start doing the cross-platform stuff.
Hope you find it useful!
Get it here -> http://farmaudio.com/farmpad