I wanted to try KDE, so I logged out, changed to Kubuntu, and logged in. Things are mostly fine, but a handful of things look off. For example, in Firefox, theres a very rigid box surrounding the menu bar that doesn't match up with the default KDE theme. 
Are things supposed to look like that, or is there something wrong (and how do I fix it?)
The Kubuntu is using the kubuntu-firefox-installer /1/ whitch is installing the firefox-kde-support /2/. Without the KDE integration the Firefox is using native (GTK ?) dialogs.
Do you have the firefox-kde-support installed ?
(1) (Kubuntu 11.10) http://packages.ubuntu.com/oneiric/kubuntu-firefox-installer
Description: Mozilla Firefox installer for Kubuntu
Enables easy installation of Mozilla Firefox on Kubuntu, via a graphical user
interface and menu entry.
(2) (Kubuntu 11.10) http://packages.ubuntu.com/oneiric/firefox-kde-support
Description: Integration of Mozilla Firefox with KDE
This is a helper application that allows Mozilla Firefox to use
KDE file dialogs, file associations, protocol handlers and
other KDE integration features.
Very old way: http://kde-look.org/content/show.php?content=13967
