All - thanks for your help. It turns out that since Qt has started enforcing rules in the ICCCM, Hummingbird hasn't had a chance to catch up with the new specs. Because of this, Qt thinks that there's an unknown window manager sitting around, and thus defaults the icon to 1-bit depth, which causes the behavior I was seeing. Outside of modifying the Qt source, there doesn't seem to be a workaround. I'm talking to both Trolltech and Hummingbird about the problem. Thanks again!