Flashing Screen followed by Windows Hang or Crash

I switched to Windows 7 from XP two years ago and have never experienced one system crashing since then, but until recently I began to be haunted by a Windows 7 system crash, or precisely, a crash caused by the NVidia video card driver.

My Dell T3500 had its original video card replaced with NVidia Quadro NVS 295 not too long ago. Unluckily, I have never got a change to enjoy the performance that would have come with this video card. What I have experienced on the contrary has been continuous system hanging, then crashing, or even (at times) BOSD since the replacement!

Symptom: Initially, the screen suddenly becomes flashing (glowing colorful dots and lines) with blurring resolution for no reason (for 3~60 seconds); then the whole screen goes frozen (for 20 ~ 60 seconds); finally it is blacked out forever, but the CPU and power indicators are still on.

Attempt: 1. I have checked the event viewer each time it crashes but found no clue. And I also attempted to reinstall the video card driver using Windows device manager which still did not help at all;

2. Installed the Windows Debugger (link) and examined the system dump file at C:\Windows\MEMORY.DMP, which said:

Defaulted to export symbols for nvlddmkm.sys -
Probably caused by : nvlddmkm.sys ( nvlddmkm+7b73bc )

So the Windows kernel mode driver nvlddmkm.sys file may be the culprit.

The interim solution I have so far is to disable the nView and dual monitor to use a single screen. I have two DPI ports on the video card, and I guess the overhead when using both of the ports of the video card at the same time may cause the issue...

Same with other users experiecing this issue. No official solution found so far...

a. http://en.kioskea.net/faq/6210-handling-nvlddmkm-sys-crash
b. http://voices.yahoo.com/techtips-nvidia-blue-screen-death-nvlddmkmsys-5316783.html
c. http://en.community.dell.com/support-forums/desktop/f/3515/t/19436822.aspx

Ref.: 1. Handling "nvlddmkm.sys" Crash, http://en.kioskea.net/faq/6210-handling-nvlddmkm-sys-crash;
2. How to solve Windows 7 crashes in minutes, http://www.networkworld.com/supp/2011/041811-windows-7-crashes.html?page=1;