Egon can you please briefly document what operations are or aren't safe for multi threading? for example rendering, displaying buffer and modifying an object/mesh which is in the rendered world obviously are not.
I'm pretty convinced that I'm sometimes having a multi-threading issue because of level loading at background. I basicly create a new world, load game objects from serialized data, attach vertex controllers and create particles. all of these are new instances. shadows are initialized later on in GL thread. no texture loading here either.
but I guess, one of these operations (or another one which I missed) is causing a multi-threading issue.