ikegami,
I don't have 5.6.1 around to test with but fortunately it worked for rational_icthus's version of Perl. Do you think getting a copy of 5.6.1 to find a work around is warranted or is the filing of a bug report sufficient?
I didn't know which version he uses, and which version the people using his code uses. I was just letting him know so there wouldn't be surprises down the line.