Thanks for contacting Plugable Support, we’ll be happy to help. I’ve just done a few quick checks here on our 10.7.2 MacBook Pro and I’m able to plug an unplug an external monitor with out any difficulties. Let’s try and figure out what’s different about your system that’s causing failures when you plug the adapter back in.
What programs do you have running when you disconnect? How about when you reconnect? What other equipment (mouse, keyboard, external hard drives) do you disconnect and reconnect? Do they work?
To try and isolate whether it’s a software problem or USB hardware, try plugging in a simple USB device like a mouse to the same port where the USB graphics adapter fails to restart.
If there’s no improvement or the problem persists, run the DisplayLink support tool and forward the .zip file that it places on your desktop over to us at firstname.lastname@example.org. Here’s a link, about half way down the page there are instructions for Mac.
Let me know what you find,