Hi Matt:
Ah, OK, I read that post, and noted that there is a solution published on the second page of that 4 page post.
The solution (which I had already applied, without even knowing that the problem existed) is to go into the BIOS and select the discrete graphics (the NVIDIA card) as the sole, one-and-only display graphics device for the notebook. In other words, disable the ability of the notebook to switch between integrated graphics (the Intel graphics device) and discrete graphics (the NVIDIA card).
Because we always have external power available when making presentations (we have to have it, to power the projector), giving up entirely on the integrated graphics does not come with any downsides. It is true that when you are running in battery mode, the battery will not last as long on discrete graphics as it will on integrated graphics, but unless you need to get 8 hours of life out of a battery (a pretty uncommon need), this is a non-issue. I can get 4 hours of battery life using the discrete graphics only without problems - I achieve this by just fine-tuning the power management settings using the "Lenovo Power Controls' application.
Just as an aside - I think that this whole business of having dual graphic system notebooks (machines with both Intel Integrated Graphics and a discrete high-power graphics card) is a bit of a PITA. It's probably wonderful for a small minority of users who need to stretch battery life to the absolute limit, but for the majority of us, it just complicates our life. My previous computer (a W500) had dual graphics, and I disabled the integrated graphics in the BIOS and ran with the discrete graphics only for the full 3 years that I had that computer. One of the first things I did when I got the new W520 was go into the BIOS and do exactly the same thing - set the BIOS up so that the computer used the discrete (NVIDIA) graphics all the time, and OS detection of the dual-graphics capability was disabled.
I don't believe that 100% of the capabilities of any computer (i.e. ability to switch graphics sources, ability to drive multiple monitors, etc.) can be used at the same time. I think it's kind of like 4 wheel drive SUVs - if you want to use the 4 wheel drive capability, fine, go ahead, but be aware that the vehicle won't perform satisfactorily if you take it out on the freeway for a drive between cities. On the other hand, if you want to go off-road, it's great to have 4 wheel drive - but when you go off-road, you don't need to travel at freeway speeds. Hope this analogy makes sense.
Michael
W520 (4270 CTO), which replaced a W500 (4062-27U), which replaced a T42P, which replaced an A21P...