Roger, your explanation might have hit the bug behind it. (I don't comment, as it is speculation any way. We all know that they fixed lots of thread-related memory leaks in 5.8.2, at least according to the document. It is not a surprise that they might had some of the bugs over killed, and now free the same piece allocated memory twice. Not neccessary to be garbage collector related ;-)

However this is not a fix, but rather a workaround, as the OP's code should be just fine, without the array you added. A Perl bug is still a Perl bug, and there is no point for application programmer to suffer from it, and worry about workaround.