Ubuntu 12.10, I can open 'Passwords And Keys' app, but then when I install the seahorse plugins, I can no longer open 'Passwords And Keys' -- when I click on the menu item/icon, nothing happens. Then if I uninstall seahorse utils, I can open 'Passwords And Keys' again. Ugh. Any help appreciated.
This is a known bug:
I'm having the same problem and it's really frustrating. According to the bug report this issue has been fixed in Seahorse itself but I don't know when the fix will propagate to 12.10. Apparently the fix also requires a fix in gnome 3.6 too: