Can someone at least give me an idea of how I can narrow down what the problem might be?
You would compile wxWidgets yourself and set the define in setup.h to 0This is a wxWidgets to GTK communications bug in drag&drop.
Not much CodeBlocks can do about it except turn off drag&drop on linux.
How can I disable drag&drop in GNOME? Please help me... :(Code#define wxUSE_DRAG_AND_DROP 1
This might cause other side effects.
If its just wxFlatNotebook thats the problem, you could compile it with the wxFNB_NODRAG flag.