It's a known bug in Perl -- nearly four years old. But your post makes no sense to me. The variable CAN be used outside the block; what can't be used (or more specifically, what has lost its value) is the internal position in the string held by the variable.
Jeff japhy Pinyan,
P.L., P.M., P.O.D, X.S.:
Perl,
regex,
and perlhacker How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart