PPTP ip-up.d runs script but doesn't execute program

Question

Hi everybody
I installed and configured PPTP and ip-up.d scripts. Everything seems to work, all three existing scripts are executed and also the echo is written to syslog but I don't get the program to start. If I execute the script manually it works like a charm.
What is the matter?
Solutions tried
PATH definition added
echo line before and after executing remmina added -> both worked
changed program execution with "sudo -u <user> remmina" and "su <user> -c "remmina" etc. also not worked
permissions checked, every script file is on 755
#!/bin/sh
PATH=$PATH:/usr/bin
echo "`date +%b" "%e" "%H":"%M":"%S` PPTP: Remmina wird gestartet" >> /var/log/syslog.log
/usr/bin/remmina

Answer 1

Hi, sorry for late answers:
..scripts that end with '.sh'. Is that the case?
[emak@PC-LE-T42-LI ip-up.d]$ ll
insgesamt 20K
drwxr-xr-x 2 root root 4.0K 20. Mär 13:40 ./
drwxr-xr-x 5 root root 4.0K 6. Mär 07:16 ../
-rwxr-xr-x 1 root root 229 3. Nov 2011 00-dns.sh*
-rwxr-xr-x 1 root root 110 16. Mai 18:45 01-remmina.sh*
-rwxr-xr-x 1 root root 162 20. Mär 13:23 02-routes.sh*
They should be correct and permissions sufficient.
Does remmina fork?
No, I don't see any procs running by executing
ps -ef | grep remmina
Last question:
you can execute it as a separate process by adding &!
I tried that with no better success.
As I wrote above, the script is executed, the echo line is written to syslog but no process of remmina is starting. I'm sure it's a dumb thing but still annoying... Any more ideas to try?