On booting up Broken Sword 4 I get an large error which stops the game from opening properly.

??? (0x005FF94C
??? (0x000001B8)
??? (0x01D426FF)

EXEPTION IN '..\..\CAGraphics2D\CATimedEffect.cpp' AT 64: Assert Failure (deltaTime>=0.0f)

Not sure whats going on there :( Any help?

I encountered a similar problem - possibly the same as yours but I don't remember the details as I've now uninstalled it. In my case, the problem was that my crappy old PC doesn't have a 3d graphics card as per the minimum requirements.

Same problem here. Nvidia Geforce GTS 250. Isn't that enough?

Edit: Installed latest driver, works better now, sound somewhat f**ked up, and crashes on the roof of the building at the beginning.