I'm seeing the same behaviour.
I have a MacBook Pro, Mac OS X 10.7.3 and just installed the most recent DisplayLink drivers from the website, v1.7 (8 Dec 2011). I've not yet tried the "1.8 Alpha 1" driver, but will attempt to when I get time. Would be interested to hear if others have tried it out yet...?
I haven't even received the USB-DVI adaptor yet, but installed the driver since I expect to receive it in the mail in the next day or two... this isn't a great sign to be experiencing annoyances before I even get the device
