I don't want to hijack this thread, so I'll have a quick note for Kevin, then get down to getting stuck anchors up
Kevin, almost every piece of our first Wingmaster failed within the first closing season

Apparently, aluminum isn't stronger than my coworkers, who are of the philosophy that 'brute force' is the answer to any problem :lol: As a result, we got 3 more and they all failed but I was able to cobble together a full set from the remains for my use. If the parts were made out of stainless, they'd be much more hardy and last longer (as you know, these kits aren't inexpensive).
Ok, when you have trouble getting a 'screw-up' anchor to come up:
1) Make sure that the tool can go in all the way (i.e. - remove any sand or pebbles from the hole the 1/4" Allen wrench fits into) These anchors are brass and brass will 'strip out' easily, be sure that you have as much contact between the tool and the anchor as you can!
2) If you can get the anchor to come up a little, blow out the debris in there and splash some water into the shell. This will wash away some more of the stuff that's clogging the threads. Turn the anchor back down, to allow the water to wash out more stuff from the other threads. Raise, rerinse and repeat until the whole anchor comes out - then rinse out the body of the anchor and the anchor's threads.
As a concerned pool owner, who has taken the effort to come here and learn how to properly care for your pool - I'd remove all the anchors in the spring, when you open the pool, and rinse them and add a little lubricant to them (both the anchor and the shell) so that you won't ever have 'sticky anchors' :-D