We had to take our liner out when some stuff got behind the liner -- long story. But after we put put the liner back in, an inch or two would pull out in a couple of places at the corners. We had the same problem you did.

We used the flat end of a plastic spatula to lift that section of the liner up slightly above where it would need to be to fit it into the liner track. The idea is to put the liner into the slot from slightly above rather than trying to stretch it from below.

Then we put the liner into the track and, while still supporting the liner from below, put a penny into the liner track above the liner. At first we left the pennies sticking out about half way, just to make sure it held, but after a week or two, we pushed the pennies all the way in so that they could not be pushed in any further. We can still get them out with a pair of pliers if needed.

We used pennies in three or four places last spring, and they held the liner beautifully when we drained our pool below the skimmers for the winter and refilling this spring.

If there are long-term ramifications of using pennies, I'd be happy to hear about them.

Joie