Dunlop 803 troubles keeping it on

[kendunn]

I just put a Dunlop 803 trials tire on my 06 EC300 (Newer type dirtstars) but it doesn't want to stay on the bead. When I hit pavement it slips right off with 9 psi in it (happened twice out of about 4 times on short rides). I left it inflated for a couple of days with like 40 psi or something as someone on Thumpertalk suggested, but as soon as I let the air out (took the valve core out thinking it would be easier to just let it all out and refill to 9 psi) the thing slipped off the bead and made a really bright "PING".

I made sure the tire was indeed seated, so I am sure thats not the problem, especially since it made that noise when it came off. Just using windex to help seat, it doesn't seem to leave a residue or anything.

Anyone had any troubles like this? I would hate to be in the woods and it start doing this, so far it has just been when I hit the pavement for the last 1/2 mile to the house so no biggie, but sooner or later the weather will break and I will want to get out in the woods!

I posted on thumpertalk, but thought it may be something specific with the rims.