At least on Mac OS X, the file menu regularly is disabled after opening the first comic after launch using the "open comic" dialog.
Woraround: use the command+O key.
Results of my analysis so far:
* This only concerns the Mac OS X application release. Installer and web start are unaffected.
* Removing Quaqua from the Java library paths fixes the menu. This is not a practical solution though because then Jomic resorts to the ugly standard look and feel, which is particular painful with file dialogs.
* Neither MRJAdapter nor Quaqua seem to have any hints on this on their sites. But maybe I need to look harder.