Grid Screen Size

I have been able to get a grid screen app up and going. It retrieves the information from my server and plays a video upon selection.

Now my issue is that it doesn't seem like the grid screen is filling the entire screen or either there is a bar on the left and right side of the screen. I don't know which. However you can see some spectres in the top left and top right once you go down from the top row. Attached is a screen shot of what it looks like and what I'm talking about.

So how can I make this grid screen full screen?

Thanks

Screenshot:
https://drive.google.com/file/d/0B7pkex ... sp=sharing