I have recently switched to the dwm window manager: http://www.suckless.org/wiki/dwm/about however I have noticed that since that change comix fullscreen acts strangely. When I click F or activate fullscreen through the menu nothing happens, I have to force an update by changing page, going double mode, or similar.
It should perhaps also be noted that even in fullscreen mode comix isn't in true fullscreen but rather has just hidden menus, toolbar etc. But the dwm statusbar is still visible. To be frank I really like it behaving this way but I'm not sure that's the intended behaviour.
I use the following software stock from the archlinux repositories:
And my own compile of dwm-4.5 with no modifications.