Frezzing when I add pistons

In any scenario/sandbox mode, as soon as I go to add pistons it freezes. Not completely, the mouse still moves (jumpy) but nothing will respond...
A tycoon game made for people who live and breathe cars.
http://phpbb3.automationgame.com/
All models support DirectX 9.0c and OpenGL 2.0
Note that ATI X1000 series cards (e.g. X1900) doesn't support Vertex Texture Fetch, hence it does not fully comply with the VS 3.0 model. Instead, they offer a feature called "Render to Vertex Buffer (R2VB)" that provides functionality that is an alternative Vertex Texture Fetch.