Hello, I have a MacBook Pro Mid 2010 connected to a Dell U3011 display via Mini-DisplayPort to Display port cable. I recently installed the 10.7.3 and MacBook Pro EFI Firmware Update 2.6. After the installation, my MBP no longer recognizes the external monitor. The monitor just stays black. Unplugging the cable and re-plugging the cable, does cause the laptop's display to go to the bluescreen as it typically would, but the external monitor is not enabled or recognized. I checked system profiler -> displays and it only recognizes the MacBook's screen. I've tried zapping the PRAM. Joel
Unplugging the power supply from the Dell u3011 monitor reset something about the DisplayPort interface and resolved my issue. I got the hint to do this from the following dell thread. http://en.community.dell.com/support-forums/peripherals/f/3529/t/19364128.aspx