I just have the the same issue, but with the GTX 560 ti on 306.23 drivers, and I hear allot of people is getting this error. I bookmarked these two links: (which helped my problem).
(Do this one first!)
http://forums.techguy.org/windows-vista/837500-nvlddmkm-sys-blue-screen.htmlThe first post, you need to read.
http://support.microsoft.com/kb/2665946Just follow these steps, or you can download the "Fix it for me" which I did. It says the GPU can't handle opening to many applications, but we know that that your GPU's can handle that (GTX 460 and the GTX 560ti). It's a very strange error from our GPU's which look's like it's related to NVIDIA drivers.
I downloaded the 306.23 drivers one month ago and haven't had any problems until in a few week's later, I started to have that issue. These links actually helped me, hopefully it helped you. I really don't know what cause this error, the last time I had an 116 code (BSOD) which was actually something wrong with the OC on the GPU. Now I OC my card to the voltage 1.050v for 6 months and never had any problems until the 306.23 drivers has been released. I don't know if it's related to NVIDIA because the 306.23 drivers was working for 3 week's than BSOD appears. I'm just guessing that the old NVIDIA drivers is still installed which you need to go into safemode and remove the 296.10 drivers permanently. I have no problem since, after I done those required step on those 2 links.
Case: Antec 300 Mini Tower Motherboard: GA-Z68A-D3H-B3 (rev1.3) CPU: i5 2500k @ 4.5ghz Cooler: Hyper 212 EVO GPU: GIGABYTE GTX 560ti (950mhz) RAM: G.Skill 8 GB DDR3 @ 1600mhz PSU: Corsair CX 750 Driver: 320.00
Been building PC's for 8 Years! 😉