Can't use built-in screenshot utility
 

I noticed today that using shift-ctrl-cmd-4 (or ctrl-cmd-4, ctrl-cmd-3, etc.) to take a screenshot doesn't work with the DisplayLink monitor. Specifically, it doesn't seem to place the necessary image into the clipboard. It clearly lets me select the portion of the screen to capture, but nothing goes to the clipboard - almost as if the cursor is read as "off-screen" when it is trying to capture the DL screen.

Has anyone else tried to use Mac OS X's built-in screen-capture commands with different results?

Same problem here. Have two Samsung 940ux monitors connected to a Mac Mini running Snow Leopard and cannot get a screen capture from either of them.

Confirmed - DisplayLink driver 1.5b7, Snow leopard 10.6.2.

This problem still exists in 1.6 beta