I don't know what I did, but the taskbar icon of osso-xterm has changed from "terminal" to a debian logo. I thought that this was because I was messing with some .desktop files, but then again osso-xterm.desktop hasn't changed and I doubt that this would make a difference, because I can start osso-xterm from the commandline and still get a debian logo. The icon in the menu is still a "terminal", but not in the taskbar.

Does anybode know how the taskbar (the bottom left area of the screen) decides what icon is displayed for which application?