Bart, your file's got magic in it. I copied the definition of the acs_pgbackup proc and the line that schedules it to your file and everything works like a train closet.
Oh yes, and I still can't see it as a permissions issue, at least from this information:
[nsadmin@swissnet tcl]$ ls -la
total 36
drwxr-xr-x 3 nsadmin web 4096 tammi? 13 16:58 .
drwxr-xr-x 11 nsadmin web 4096 tammi? 2 17:01 ..
-rw-r--r-- 1 nsadmin web 2787 joulu? 22 22:26 acs-pgbackup-init.tcl~
-rw-r--r-- 1 nsadmin web 2812 tammi? 13 16:57 backup-init.tcl
-rw-r--r-- 1 nsadmin web 3958 tammi? 13 16:58 cache-control-init.tcl
-rw-r--r-- 1 nsadmin web 1408 tammi? 13 16:01 cache-control-init.tcl~
drwxr-xr-x 2 nsadmin web 4096 tammi? 13 16:24 CVS
-rw-r--r-- 1 nsadmin web 1451 joulu? 22 21:47 zz-postload.tcl
-rw-r--r-- 1 nsadmin web 840 joulu? 22 21:47 0-acs-init.tcl
Life is a mystery.