When using the Rulers tool in xScope with multiple monitors connected to my computer part of my screen turns grey. How do I fix this?
 

If you are running into this issue, be sure that you are updated to at least version 3.5 of xScope, which resolves the issue. To run xScope 3.5, your computer must be running OS X 10.7 Lion or newer.
 

If you are not running Lion, there are two things that you could do to resolve the issue. First, try resetting the tool by going to the Rulers menu and selecting "Reset Ruler." If this doesn't work, you can try disconnecting your second display and reconnecting it to resolve the issue.