I have posted a few threads the past couple of weeks trying to get info on my new XT derailleur, shifters and so forth. It took some time to get the derailleur adjusted and working right. The bike shifts up and down with out any problems, except in 5TH gear. When I am in 5Th gear and it doesn't matter whether I am in the granny in front or middle, the chain keeps slipping, and slipping bad to the point where it is dangerous to be in that gear.All other 8 have no problems whatsoever. I took my wheel off and really looked at the cassette, to see if I had a broken or bent tooth, but it looks fine, at least in my eyes. So what do you all think, bad 5th gear cog? At this point I don't think it is the derailleur.