Yes, I've really only had this problem with AmeriColor - their Burgundy and pinks most lately. No problem with their Turquoise. I'm not sure why it happens or how to remedy it, but it seems isolated to this brand and certain color families (for me, anyway). I try to dry under very controlled conditions (quickly) and use icings as thick as I possibly can, because colors seem to set more stably this way, but still some troubles. An email to AmeriColor might help if you've got the time. I can't pursue this with them right now, unfortunately.