Hello there hyder711,
My non-ref XFX HD 5850 ZAFC v1.3 unlocked "only" with Trixx v0.4.21. I should add that the operating systems I've used it on are XP and Vista 64. If both you guys are using W7 then maybe try running Trixx in XP(sp2) compatibility mode.
I'm not sure the mod for 5870 in the video would be the same for your 5850. First things first.. lmk which voltage regulator you have? Usually NCP5395T or uP6213 on non-ref cards. I'm guessing NCP5395T as that's what I have on my XFX.. Chudos probably has uP6213 on Sapphire blue pcb. To speed things up get the resistance from FB to ground with card out of pc.
Welcome to OCN!