"kubuntu-desktop" is the package I installed, but I'm not 100% sure it is the right package to report against.
When using Firefox or Thunderbird in Gnome's Unity desktop after having used KDE4 once, the fonts in (at least) these two applications are messed up and cannot be restored with Gnome configuration tools (including MyUnity, "extended settings" and the like). See attached screenshots.
I tried removing Firefox's profile (~/.mozilla) which didn't help. I removed ~/.kde, ~/.kderc, ~/.gtkrc-2.0-kde4, .compiz, .dconf, .gnome2*, and almost everything else, and it didn't help. Only after removing *all* hidden directories and files - and thus restoring Gnome font settings to the defaults too - did Thunderbird and Firefox regain the ability to correctly display the fonts in use.
Note that the actual font which Firefox used for its UI *did* change when I changed the font in the Gnome settings tool. Only it looked totally ugly (without hinting?).
I would expect KDE4 not to touch Gno…
kubuntu-kde4-meta (Ubuntu)
Undecided / Confirmed