Traditionally, this was solved by making wmiirc (1) emit "Start
wmiirc" to /event at startup and later (2) exit if they see "Start
wmiirc" inside their /event processing loop. In this manner, new
instances of wmiirc terminate previously existing ones.
I don't know why that mechanism was removed from the default SH
wmiirc. It did exist in the past, however.
It still exists. See ll. 2-4 and 211-212 in cmd/wmii.sh.sh in the source
tree.
However, spawning wmiirc from the Action menu does not work for me as
well, although with different symptoms: No keybindings work thereafter.
--
Thomas Dahms