I'm using 3.3.6.1 and I noticed that if I don't specify a custom icon when compiling, the compiler uses the last custom icon I compiled with. In other words, if I don't specify any icon, I do not get the AutoIt default icon. I get whatever was the last custom icon I specified. Seems to make no difference if I store settings in script or not.
I know the work-around is specify a custom icon. But it's kind of annoying if I have a quick and dirty test script and compile it, it has the same icon as the exe from my last project. I don't understand where it's pulling the information from.