i use 2k primer sealer yes with approx 10% or less solvent. I use 2k HS clear with no solvent. I use a mix of waterbase and solvent basecoat. Come to think of it, the last two colours i sprayed where this was apparent was a royal blue and black, both in solvent. I use the same slow speed reducer for everything.
The bonnet i did recently had a reaction with some previous paint and i had to dry flat this and spray the colour on really dry. I managed to get the colour on ok after about 10-12coats of real thin base, then cleared again with no solvent. The day after the hazing effect was quite apparent, probably the most noticable ive ever see it.
oldBodyman, your comments are the most interesting and i will definatly try leaving the base over night to see what happens!