I have had the same problem, and have had to change styles, and all is visible again..... having played "pin the donkey" trying to close the window.
In fairness Stardock, have to say instructions for your wonderful things are very scarce in help.
I have to say I personally miss the ability to change the borders of active and inactive windows as per windows 3.1 !!
if there is a layman's way of doing so, then would love to know.
Many thanks
Steve