Is it half of the screen of your thumbnail or your program?
What computer operating system is your Premiere Elements 11 running on?
By any chance are you editing .wmv files? If so, have you looked at the announcement at the top of the forum which calls attention to a 1/2 wmv display related to a recent Windows update?
Also several threads on the subject including:
If the above does not apply to your situation, please give more details relating to your source media and your project settings and what you are seeing.
I agree that the Announcement was a great idea, but it's too bad that no one is seeing it.
As I mentioned, maybe flashing red neon?
We tried though,
But, the great news is that a lot of interesting and informative discussions have come forth from that 1/2 wmv display and kb thanks to Microsoft.