I posted the following a couple of weeks ago in another thread....
"I've tried several poles and they all have the same basic design problem. They adjust by turning a threaded PVC-like ring on the outside of the handle. They work great.... for about a month and then the threaded area gets dirty, or something, and starts to bind up. It will either fail so you can't turn it at all, or it will not tighten enough and does exactly like what you are complaining about...
Went to my local pool store, not associated with any brand name pools stores, and they suggested I use a pole they carry. All the workings are inside. So I bought it (about $35) and I could not be happier. I was impressed enough to buy another one a few months later. At the time I did not look at the brand name, I didn't really care until I read your post.
I went out to look and was surprised that it was a "Pentair" product. I didn't even know they had a pole product. Under the Pentair brand is the name spelled, "Lifegard #812-16 Tele PL R191046). I've only had them about 6 months, so time will tell, but, so far, they are way better than any other telescopic poles I have ever owned."
Jim R.