i had my house painted with Behr exterior satin. the hardie siding has an uneven luster when viewed at an angle, so we added another coat to no avail - all sprayed on. same paint/painter/sprayer on the garage door did not show this problem after just one coat. the hardie is primed, so that hopefully is not the issue. i will admit that it was up for a few years before painting, could that be an issue? it was a dry day, windy first coat, calm the second.