Yup, what Trevor said. Despite the fact that you've got the latest video drivers, it doesn't mean you've actually got the latest video drivers.

More detail:

I was having trouble with my laptop, problems with multiple monitors, docking and undocking, and sleep/wake. It just so happens that the laptop was also an HP model.

Even with the latest HP-supplied video drivers, I was still having the problems. One of the problems I knew (from release notes) was specifically solved by a new driver from the video chip manufacturer, but that version of the driver had not been packaged by HP yet and was not available through HP.

See, the laptop manufacturer doesn't repackage the drivers for their laptops immediately after the video chip manufacturer releases a new reference driver. There is often a long lag period and sometimes the laptop manufacturer never gets around to a release. And because the laptop and video card manufacturers have worked out deals where the video card people don't want to have to support all the laptop owners, they deliberately cripple the reference drivers so that they won't install easily on the laptops, and you're forced to go through the laptop manufacturer for support. I find this an awful, irritating practice, and I'm pretty sure you've just run afoul of the same practice.

In any case, installing the latest reference driver via one of the methods mentioned in this thread completely fixed all the problems I was having on the laptop. I was angry that I actually had to *hack* a video driver installer to fix my problems, but now that I've done it, I'm a happy monkey.

My issue was with ATI drivers, but I'll bet it's exactly the same with the Nvidia drivers in your case. Have a scrape 'round the net for utilities that will let you hack reference drivers onto laptops.