Widget redrawing when the window resizes sometimes messes up.
GtkLabels sometimes redraw without clearing up the underlying background on window resizes. The way DND data types are set in GtkWidget really needs to be fixed. This is pretty high on my priority list, and I'll get to it as soon as the column list widget is done. The correct way dnd data needs to be set is to have a additional keyed data type with GtkWidget, which is applied to the widget's window upon realize. Also, adding support for drop zones might be nice.