Comment 7 for bug 196429

I found this thread because I caused myself a similar problem (greyed-out button in the gnome print dialog box) by making an incorrect entry to the hosts file on a fresh install of 8.04 (with the home directory contents restored from backup of 7.04).

Just for info then,
127.0.1.1 boxname
instead of
127.0.0.1 localhost.localdomain localhost boxname
caused the "greyed-out button" problem for me (where "boxname" is, of course, the name of the localhost).

WARNING: although correcting this entry sorted the greyed-out print button issue for me, it created a follow up problem. The menu bar of a newly opened application was melded with the applications-places-systems panel at the top of the screen. That made the desktop pretty much unusable. Newly created users were not affected, so to get around this I just created another user for myself.