Binary package hint: gnome-themes-standard
When starting any GTK application, I get the following spew on stderr:
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:620:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:626:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:632:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:639:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:645:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:651:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:657:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:663:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:669:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: /usr/share/themes/Adwaita/gtk-3.0/gtk-widgets.css:675:27: Whitespace between 'url' and '(' is not allowed
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: <unknown>:1:0: Expected an identifier
(gnome-calculator:3760): Gtk-WARNING **: Theme parsing error: <unknown>:1:0: Expected an identifier
Thanks for your report. This is confirmed on Oneiric.