Can't speak for the kx133 chipset, but I have gotten 2 different GFDs (Leufkin + Northwind) to work with the Slot A T-Bird on a MSI K7Pro. I bet the only problem you might encounter is at high-end clock speeds.
Check over at AMDZONE. They have 2 threads going, one for KX133 and the other for Irongate. GFD's are working fine, infact, taking a 700 T/Bird upto say 900 works but faster unclocked chips have probs.