Hi,
I've just been trying to reproduce your problem.
I don't have a MBP running Windows but I do have a stock Dell Latitude running Windows 7 x64.
So far I tried a NL571AA HP adapter on a P2314H with 7.9 & 7.8 DisplayLink software and haven't seen this issue.
Could you try updating the Intel graphics driver for your notebook?
I'd recommend picking up the
latest version.
If you have any issues with the graphics driver installation please see this FAQ:
http://www.intel.com/support/graphics/sb/CS-033915.htm
Thanks,
James