Index: openttd-1.0.2/src/video/sdl_v.cpp
===================================================================
--- openttd-1.0.2.orig/src/video/sdl_v.cpp	2010-01-15 17:41:15.000000000 +0100
+++ openttd-1.0.2/src/video/sdl_v.cpp	2010-06-28 22:59:49.000000000 +0200
@@ -468,6 +468,8 @@
 {
 	char buf[30];
 
+	putenv(const_cast<char*>("SDL_VIDEO_X11_WMCLASS=openttd"));
+
 	const char *s = SdlOpen(SDL_INIT_VIDEO);
 	if (s != NULL) return s;
 
