The freeze occurs because of an issue in the video driver for this graphics card. Downloading the latest driver will resolve the problem.
Go to the NVIDIA website and download the newest driver for this graphic card. The current driver version is v 220.127.116.1108 (dated 18.02.2009). This update resolves the freezing issue.
In order to verify if a particular problem can be linked to a hardware driver, you can boot Windows in Safe Mode (Press the F8 Key during boot to do so). Once you have booted in safe mode, no third party software drivers will be active, and your display may be limited to 800x600 resolution. If the problems that you have been experiencing disappear when booting in Safe Mode, then you can assume that the problems are linked to a third party hardware driver.