[mike@af]

My guess is that the paint was thinned, rather than reduced. Thinning can create chemical reactions that create a bad surface for the paint to adhere to. Reducing is like thinning, except there is a special "thinner"/Reducer that is made for a certain paint.

Or it could be that the surface was not preped properly. What primer did you use? If you laid a acrylic base over an enamel primer, all hell will break loose.

There are some other guys here that may have some suggestions as well.