** calendar_admin.pl is the problem... **
Good. It helps to be accurate when requesting assistance.
** can't chmod cg-bin directory or files - they're all 755 **
That seems to contradict your previous statement of "chmod 777 all files and dirs". Or is that not where you uploaded the CalendarScript script files to??
** 755 - might that be the problem? **
755 should be all that is needed for the script files to run. Whether they'd be able to write to their data files, I don't know but I doubt it would cause your described problem.
** I thought that the calendar_admin.pl script used/called javascript in some way. **
There are some uses of JavaScript by the calendar_admin.pl script but none would cause the error you described. When JavaScript fails, it usually produces a browser JavaScript error.
I suggest you look at the server's error logs for the time when you tried running the administration script to see what error(s) were reported.
Dan O.
------------------