For what it's worth, I had a similar problem. The solution for me was simple, but I had to stumble upon it.
On my sled, there are 2 set-screws and one compression nut that hold the pole in place. When I would make pole height adjustments, I would first tighten the compression nut (which required no tools), then I would tighten the set screws. It turns our that this was (somehow) shifting things off-center. So, when I'd balance the sled and turn it 90 or 180 degrees, it would start to lean (a lot).
While trying to figure this out, I happended to tighten the set screws first (without having the compression clamp already tight). Poof. fixed. The sled balances true.
Somehow, that comptession clamp was torquing the assembly so it was off-center.
Anyway, maybe this will help someone with a similar issue.
