I bet you're running KDE 3.1 installed via Fink
I bet you didn't read the release notes
In KDE 3.1 installed by Fink, the default window manager is set to quartz-wm, if it exists. To change this behavior add 'export KDEWM=kwin' to your .xinitrc file.
On another note, using exec and & for the same command is not advisable. The & runs the job in the background, exec runs the command as the existing process id and replacing the calling process. By running exec and & at the same time, you're really negating the entire reason to use the exec command. What is really happening in this .xinitrc is, you're running startkde, which is starting up quartz-wm as the window manager. You then tool around in KDE get annoyed as you don't want to be using quartz-wm, you then exit so you can try again. After you exit KDE, the startkde application then ends. Next you then run the kwin application, in the background. Ofcourse, X11 stops when it reaches the end of the .xinitrc file, so, you backgrounded kwin, and then X11 promptly exits as the end of .xinitrc has been reached, and the process exits, which then kills the kwin process that was spawned that you didn't even know was spawned. If you didn't have the &, when you quit KDE, you would have had kwin itself startup.
Brian
PS: Yay! post #500, and it was actually helpful (hopefully)!