I believe that you have encountered a variation of a known bug.
For More Information see: Edit Layout/Report in Pro 11 Screen turns to gray when using either of the scroll bars.
This is one of many acknowledged bugs that can be found in the Known Bug List thread here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: http://www.4shared.com/file/8orL8apk/FMP_Bugs.html
Thank you for your post, and I apologize for the late reply.
The response from PhilModJunk is correct (Thank you). Our Development and Testing departments are aware of this issue, and I have attached your post to the original report. No additional information is available at this time.