you gotta be careful when mixing shit into those cans, the formula for propellant and solvents is a bit different to your run of the mill paint.
do a test swatch (spray some burnerchrome and some of the chrome you're going to mix with in to an old lid) and see if they mix properly or separate completely. if they're separating, you're going to get sub-par results from the paint. it's for this reason that you don't mix non-chrome paints in to empty metallic cans.
either that, or you shot your valve when mixing (pushed too hard on the seal).