As latex paint dries it grips and pulls the surface, just as you would put your hand on a sheet of paper and grip it, making it wad up. The grip and pull action will pull the old paint loose. Oil based paint, on the other hand, lays out flat and relaxes; therefore latex paint over oil based will pull it loose almost every time.
I would redommend that you sand the affected area, prime it with Kilz II, and paint with two coats of the latex. Remember, latex enamel takes 7 days to cure completely, although it will skin over and feel dry to the touch in 2 hours.