For what it's worth, this happened to me today after installing the 10.7.3 combined update. :(
I'm using the Plugable UGA-2K-A (DL-195) with a HP ZR24w rotated at 90deg (1200x1920), plugged into one of the USB2 ports on my Thunderbolt display. I run the latest model MBP 13".
I rely on the second rotated monitor for software development and hope an updated driver can be made available very soon. A black screen is quite discomforting...
jpap
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