linuxmint/Cinnamon — pull request #1104 by mtwebster (2012-09-10 01:58:42+00:00)
Title: Add 'window-marked-urgent' to the signals listened for in the window-list applet

Tries to address #1072

The good news:

Fixes window-list alerts for XChat, Empathy.

The bad:

Does not fix Pidgin - I believe this to be a Pidgin issue, not Cinnamon/Muffin.