As someone pointed out the file permissions also play a role in this:
root@mrk-fujibox:~# ll ~/.profile
-rw------- 1 root root 31 Mar 6 13:54 /root/.profile

markus@mrk-fujibox:~$ ll ~/.kde/Autostart/kufbootstuff.sh
-rwx------ 1 markus markus 284 Dec 16 19:52 /home/markus/.kde/Autostart/kufbootstuff.sh

The filename kufbootstuff.sh can be changed to anything.sh
You can set the executable bit with: chmod u+x ~/.kde/Autostart/filename.sh

You also need to logout and login again for the file under .kde to get loaded, or just do: xhost local: