Open mIRC.

Maximize status window if not maximized.

/server irc.swiftirc.net (or any network)

/join -n #aaaa,#bbbb,#cccc,#dddd,#eeee

Click Tile Horizontal

In the treeview:

Click #aaaa
Click #bbbb
Click #cccc
Click #dddd
Click #eeee

Maximize #eeee channel.

Click Tile Horizontal. (Channel Windows seem to cycle really quick) The bug?????
Click Tile Horizontal.

The MDI window for the #eeee channel is missing its titlebar.

Maximize any channel or status window.


Duplicate Icons.

Tested on Windows 7 and XP.

maroon tested on Windows 7 and got the same bug.

https://i.imgur.com/8OcVuwA.png