Forums Bug Reports v7.1 receiving a specific non-UTF-8 strain

I was observing some odd behaviour with some non-UTF-8 strings of text I was receiving as a result of clients connecting with exotic realnames/gecoses.
It took me a while to narrow it down, but I think this is an accurate description.
Paste characters from the following ranges one after another and send it to yourself on an IRC server without UTF-8 encoding via //.raw -n PRIVMSG $me :<string>

0128-0223
0128-0191
0192-0247
anychar
anychar
anychar

The anychars are optional, but the result is much more pronounced when you add a minimum of 3. E.g.
//.raw -n PRIVMSG $me : $chr(0221) $+ $chr(0181) $+ $chr(0240) $+ 111
vs
//.raw PRIVMSG $me : $chr(0221) $+ $chr(0181) $+ $chr(0240) $+ 111

This result, by the way, it the same as doing a $utfdecode() on the whole string. So basically mIRC seems to be decoding an unencoded string.