Currently using lubuntu 15.04
when change theme to lubuntu-default or lubuntu-dark-panel via "Customize Look and Feel" panel.
Running gvim in a new console will show the following error message...
$ gvim
/usr/share/themes/Lubuntu-default/gtk-2.0/apps/thunar.rc:55: error: invalid string constant "thunar-statusbar", expected valid string constant
I believe it should be reported at the Launchpad site against Lubuntu-default theme since LXDE developers team have no relation to that package, sorry.