If you have access to a paint supply shop ask them for a tin of 'panel wipe' (some places call it different names, but they should know what you mean). Last time I bought some it was around £10 for 5 litres, but it lasts for ages. It's also great for removing sticky labels, and also for cleaning before applying sticky tape/pads.
Spray shops use it on body panels, the idea being to wipe the panel/part before you actually touch it. Then do the prep, then wipe again before painting. Do this before every coat (unless you haven't actually touched or rubbed it down).
Anything from oil off your skin, furniture polish, cleaners etc can cause a reaction in paint. And it's a total pain having to start from scratch again!
Applying too much paint can also cause a similar result.