Have you set Code: chmod +x /home/user/delete_syslog_script.sh to make it runnable?
chmod +x /home/user/delete_syslog_script.sh
Also, I'm unsure if it's a good idea to use the /bin/sh shebang. Afaik, you should be using /bin/bash and let maemo's symlink to ash work.
#!/bin/bash yes pipe (sorry, I'm using opera browse and I can't use pipe symbol) rm /var/log/syslog