Clean it before you put on the primer, if you didnt. Only use acetone or thinner. Other solvents may have oils and silicones in them and not apply well with some paints.
Just the natural "oil" on your skin is enough to ruin a paintjob.
You may also have a problem with the filler, if you put on to thick it will go on a "breathe" for some time when its only cured on top and the gasses and oils releasing from the bondo/filler messing the paint up.
Use the kitchen oven (if it fits there) and you dont have a girl or kids at home (it stinks) :P
I usually paint parts and put it in the oven for some time at 30-50 celsius to cure the paint and bondo/filler. (dont use stuff you will put food on later, put in some foil to prevent dripping... you know, common sense)
You can also wait 2-3 days if you know that you applied to thick layers of the filler/bondo to be sure that its not causing paint problems.
Great build btw!