I also have the same issue, but only am using one monitor!
System here is Windows 7 x64 with all patches and updates installed.
Video card is a EVGA Nvidia GeForce GTX 750Ti
I am using GW Pro v1.2.109.
Each time I reboot the mini-viewer moves down and to the left a little bit - a few pixels.
It didn’t do that in the older version.