Originally Posted by sublime2
Are you sure your making connection at all points before twisting.getting 2 out of 3 hooked could cause this problem.also,the rubber seal that gos on top of GD and the bottom of sink drain, is it new or are you reusing the old one?
There are only two points of connection - both are engaged. Everything but the sink itself and some of the plumbing is new.
I ended up cutting a thin rubber gasket and placing it between the mounting bracket and the rubber seal. That definitely firmed things up - I had to use a screwdriver to tighten the bracket, which is what the instructions generally call for.
It still was a little loose, but the amount of movement was much lower. Between that and adjusting things so that the pipes are against a piece of the cabinet I think I'll be fine. But, I'll definitely keep my eye on it.
If it still seems to be a problem I'll try their "help number" - they have lifetime warranty with in-home repair for any kind of manufacturing defect.
Thanks for the tips though. The unit itself was apparently rated top in 2009 Consumers, but it seems like the mounting has some tolerance issues.
Thinking about it before using a gasket I'd probably try plumber's putty in the same spot - it would hopefully create a little more friction.