Both my girlfriend and I have dunlop 803 tt on our bikes (me, 09 ktm 300xc) (her, 07 ktm 250xcf-w with a 320 big bore kit) We run between 10 and 13 psi, she likes it harder. (hehe) We both did the Virgina city grand prix, a very rocky desert race. The tires did wonderfully. I don't know why you both went flat. You do need to change your riding stile a bit with tt, less slippin more grippen. I have wondered about bigger bikes like the k5, and how they would with a tt and all that instant power. (wheel spin) I am thinking that you may have spun them off the beed. The 803 lasts me the some as a knobby, but works better. I was planning on ordering the mt 43, I hope I don't have the same luck that you guys had. We both love the tt and I doubt we will go back to knobs.
P.s She got 1st in the woman's class and 20th over all. I got 6th in open nervis, 44th over all. She beat me by 15 min. She rocks. Thare was 501 racers this year.