Microsoft has just released a set of updates for Windows Vista, divided into two separate update packs. One deals with performance and the other with reliability, and seems to fix quite a few issues with video drivers and hibernation. It's very likely that Microsoft will release these through Windows Update in the near future, but if you are having problems now, you should take a look at the list of bugfixes and consider installing them manually. I've copied the list of fixes here so you can quickly read through them, with links to the source articles that contain the downloads. Compatibility and Reliability Updates

Download Compatibility and Reliability Updates from Microsoft KB Article Performance Updates

Download Performance Updates from Microsoft KB Article I've just installed both of these updates myself, and will update the article if I encounter any issues with them. It's worth pointing out that this update is supposed to resolve the issues with copying large files.