I found another perl5 bug by accident. It can be reproduced with perl-5.8.8 like this:
$ perl -le ' $a = "Hello"; for ("$a") { lc $_; print }'
hello
It happens only if a variable is given within the quotes.
I discovered it by writing a support script to convert a standard Module::Build distribution to Test-Run-Builder. In this context, I needed to add another entry to the MANIFEST file, and used sort { lc($a) cmp lc($b) } on the existing lines and an extra line placed in quotes. And then when I ran svn diff I found out it was in lowercase.
On a slightly different note, I also spent a lot of time isolating a hard-to-isolate vim bug on Mandriva. It turns out to have been an incompatibility between the vim source and the compilation flags, that surfaces only when using the vcscommands.