This isn't really a windows 7 bug, but more a RO client issue..Disabling aero really isn't going to do anything either.
This weird bug actually persists across a multitude of operating systems/configs according to my own testing.
At work this happens consistantly where I'm playing on OS X yosemite running a windows XP virtual machine through parallels desktop. I would assume this same thing happens with a native windows XP install as -most- issues in a VM actually transfer to the real thing.
Windows 8.1 x64 regular install on a sony vaio in bootcamp, and in a virtual machine has the exact same issue. Windows server 2012 R2...same exact thing. Wine - guess what? same issue.
Your best bet is to just play windowed and click anywhere outside of the RO client, or alt-tab though i find that to be annoying as the display takes a couple seconds to sync with resolution changes.