This has bugged me for a while, but I've simply changed the option to workaround it.
mIRC does not support the %#Channel prefix usually - when you successfully join, mIRC sends PART immediately after.
By adding '%' to CHANTYPES in the 005 raw, mIRC is quite happy to join the channel, as one might expect.
The bug is when you try and use /list (or /listx on IRCX) - mIRC successfully reads the channels, but filters them as non-text channels (Hide non-text channels is turned on by default)
My suggestion would be that mIRC supports channel prefixes in the list dialog that are found in the CHANTYPES - or disable the hide option by default
- What is the value of this option now, with many servers supporting UTF8 channel names?