As pointed out by alxgudo and martintxo here, it was possible on Gnome installations for buttons to not show up. That happened because I didn't declare a dependency. This should be fixed in the latest release.
I also added binaries for Debian 5.
Ubuntu 8.04 and Debian 4 seem easy to add too, if anybody wants them. Perhaps a better idea would be for somebody who actually knows how to build packages to have a look at what I'm using to build the binaries and see if they need improvements. (The files are in the "package" directory in the Linux tarball.)