First of all, I'm not 100% positive that the main question I've written here is actually the problem, but I have a hunch that it is. I've wrote a simple Gtk# application in Mono awhile ago, and gave it a custom ICO as its icon file. Worked great.
Recently I went to change out this icon to a different one, but when I build and run the program it still shows the icon. I've made sure that I've updated every reference to the icon file to the new one, and have completely deleted the old icon off the hard drive altogether. But it still shows up in the Launcher when I run the program.
I am assuming this means that Gtk caches the icons somewhere in Ubuntu and I probably need to force that to refresh. Any advice?