Forums mIRC Help /list doesn't show channels starting with ##

Channels with names starting with ## aren't showing up in the /list window in mIRC 7.17. For example, connect to freenode and do "/list -min 500": among the channels returned by the server are ##c++ and ##linux (as can be seen via /debug) but these do not appear in the window.

edit: seems any channel name that doesn't start with a letter won't show up: at least "#-", "#", "#_", "#0" don't