I may have learned something yesterday. I love Microscale Liquid Decal film, because it's easy to apply and is super thin, but there is one problem that often crops up; the decals will curl up at the edges, and Micro Set and Micro Sol don't seem to help. I often need to apply some white glue with a toothpick, wait until it's tacky, and then try to stick the decal down. A right royal pita.
Yesterday I tried Humbrol Decal Fix, which I picked up at the Hobbycraft in Telford. Worked a charm! It was only a couple of decals, but this may be the solution to the problem.