Luc contacted me directly first with this problem. To me it smells like something similar to the SElinux functionality. Meaning that depending on how a script is called the kernel allows loading shared lib objects from non-standard directories, or not.
in reply to adding libs in a setuid-perl script
Unfortunately I don't know Solaris 10, and in fact I'm nowadays very much removed from any sysadmin work, so I don't really know how this might need to be changed in order to work.
I don't think that the perl binary itself does anything special if it's running under setuid - and the fact that the script works when it is not running setuid would seem to indicate that things like LD_LIBRARY_PATH are in fact set correctly.
Guess we need someone with Solais 10 know-how...