Can you post the *exact* text of your scripts? There may be something trivial that you're not catching, but that having "many eyes" on the problem will find quickly. (Think of it as a highly parallelized architecture with people instead of microprocessors ;-).
If you can post both the calling script, and the required "$script", that would be the best.
s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/