PS freezes during lasso selections

I just picked up a new desktop and the darn thing is lighting fast in PS now. However, it cant seem to handle the lasso selection tool. Does this tool take a lot of CP power or is there some other reason. It seems that halfway through the selection the screen freezes but if I continue to make the selection, even though I cant see what Im doing, when I release the mouse button, the selection works.

Which operating system?
Which version of Photoshop?
How much RAM do you have and what are your settings in your performance panel in your preferences file?

How much memory have you allocated for PS to use?
How is your Scratch Disc set up?
Has PS shut down improperly at any time?
Do you have PS set up to use the GPU?