I've upgraded to the latest version of IO::Uncompress::Gunzip available on CPAN and continue to see the problem. I'm using 32-bit activestate perl 5.8.9 along with a variety of modules (some rather old) for a production tool.
in reply to Re^3: IO::Uncompress::Gunzip to scalar takes hours (on windows)
in thread IO::Uncompress::Gunzip to scalar takes hours (on windows)
The plan is to upgrade to a more recent version of perl and required modules, but the time to do that and get things tested has not been forthcoming. However, I expect this will solve the problem.