P2311H, input timing is not supported

I've seen a few people with this same problem but have yet to find a solution that makes sense.  Really hoping someone has figured this out.

I just bought two new Dell P2311H monitors.  The recommended resolution for both monitors is 1920x1080@60Hz.  I'm running Windows 7 64-bit OS and my laptop has one VGA output and one HDMI output.  In order to run dual monitors, I have to run a VGA from the laptop to my first monitor and then an HDMI with a DVI converter to the second monitor.  I was running this just fine with my ViewSonic monitors for over a year with no problems.  I also made sure that I had the latest drivers from my NVIDIA graphics card.  I set the resolution for both monitors to 1920x1080@60Hz which Windows shows as the recommended setting for both.

The problem: The monitor connected via VGA is working perfectly all the time.  The monitor connected via HDMI-DVI is working intermittently. Sometimes it will work fine for hours.  Other times it will immediately black out for a short period, then flash back on for a while, and then black out again.  When it blacks out, I get the following error message:  "The current input timing is not supported by the monitor display.  Please change your input timing to 1920x1080@60Hz or any other monitor listed timing as per the monitor specifications." 

I even tried reducing the resolution and I'm still getting the intermittent black out.  Hopefully this is enough information for someone to point me in the right direction.  As I said, this set up worked perfectly fine for over a year with the exact same laptop but different (19") ViewSonic monitors.

Thanks,
Chris