I have only used the adjust a glide brush once, but have really no idea how or when to use it.  I cleaned my friends apartment with it like 3 years ago.  I'm too afraid to try it on any other carpet.  It still has carpet fibers from that day.  I cleaned it a little bit but it was heavily loaded with carpet fibers so that is part of the reason it scares me.

No fancy sprayer here 

I had that adjust a glide and had the same problems I would use pads before the brush. Also did you break the fibers in on the brush by running on concrete for about 15 minutes it helps spread out the fiber tips of the brush, if you haven't done it double check with manufacture prior to doing.