I've only had this problem if I sprayed to thick (lacquer gloss, over enamel paint). The lacquer "attacks" the paint below, and it's basically screwed(for lack of a better term!).
I only ever had small areas, that were easy enough to sand down, re-paint and re-gloss.
Some years ago, I bought a quart of Minwax Gloss lacquer, thin it about 45/55 (gloss/thinner) and run it through the airbrush. I use a cleaned out 1oz. paint bottle to mix and store small batches. Key is...do a couple light coats, then you can get a bit heavier with em.
For what it's worth...that quart of gloss was about $10...and it has done over 100 models...most were 1/72...but still a heck of a lot cheaper than buying "special" model clear gloss lacquer!