My output doesn't match yours, even when I do have the terminal in UTF-8. But that doesn't bug me since, as ikegami points out, the string lengths I get are wrong when I use non-ASCII characters:
$ perl -l
print length 'ñ';
Now I wonder how is it possible that I've never encountered any problems with this :^). Thanks!
(Please treat my english text just like Perl code, i.e. feel free to notify me of any syntax, grammar, style and/or spelling errors. Thank you!).