It seems to me that HTML-Parser issues an erroneous "Parsing of undecoded UTF-8 will give garbage when decoding entities ..." warning, if you pass it UTF-8 encoded content to parse, even when you specify "attr_encoded => 1".

I have submitted a detailed bug report (with a suggested fix) to http://rt.cpan.org/Public/Bug/Display.html?id=29089 , but could somebody please confirm this as a bug?