Kelvin Ho - 2010-03-22

This isn't a bug in Comix, but a bug upstream in gtk that has already been patched:

Ubuntu people also have an entry on Launchpad for it:

It's already in Lucid, not sure about Karmic.

My guess, since it's not a party crasher, is to just wait it out until Lucid comes along. The alternative (getting the latest gtk+ sources and compiling yourself) might introduce more problems than it solves, IMHO.