It worked fine after I first installed it, then it just started giving me this hassle every time since. Half-Life is totally patched up to date (which knocked Op Force into not working grr), same with mouse, vsync is on, latest drivers etc. It sucks as I love using WorldCraft... I *had* thought it may be a bottleneck with the graphics card lagging behind the processor. Is that even possible..?
I may even go to the extreme of building a new "Half Life" friendly PC...
EDIT: Discovered the game runs fine in software mode, and very well in OpenGL mode... D3D issues?