just an update and for anyone else with the problem. i bought a strip of the "channel lock" for about 3 bucks..about 8 ft of it.there are 2 kinds at my local pool store..last year, the stuff i bought seemed quite thin and too wide so i had to cut it..was easy to break with even a rubber mallet as well. this time, i bought narrower stuff that seemed a bit thicker. used water at max tap heat that i then nuked for 5 minutes..not boiling but very hot, lowered the pool level about 4 inches (it had been about 3 from the concrete surface before i started) and it worked great. i fixed about 10 spots ranging from about 2 inches wide to the one that started this which was actually 8 inches wide! it's a 20 year old liner or so so it's pretty stiff, but the hot water stretched it nicely and i was able to do a one man job on it. very pleased. i had tried the hair dryer last night to get a sense of how easy to pull but the hot water was a lot safer of course and i think did a better job stretching the vinyl over a larger section as it covered more area..