Gnome file associations, AIR and ZIP

I thought I'd conquered the black-box that is gnome file association configuration (see http://darrendev.blogspot.com/2008/05/gnome-whether-under-redhat-or-ubuntu-is.html)
but I'm stuck again.

Since installing Adobe AIR for linux it has associated itself with zip files. So the icon is now AIR, and the default action is to open AIR (and so when I double-click a zip file it gives me an error saying this isn't an AIR file). The only way I can open zip files is by right-clicking them now.

How do I remove that association and restore archive manager? I don't know. AIR hasn't installed anything in /usr/share/mime. And I cannot see anything in the myriad of configuration directories that live under my home directory. So, where else does gnome get its file association information from?

Please help!