mackenzie, It sounds like your lcd sleep is trying to kick in while you watch video. Try the following settings.
Settings>LCD Set>
darkle=0
black=0
Settings>Power off>
Off time=0
This will turn off any sleep settings.
You could also try extracting your firmware using s1fwx and running repair.bat and then uploading it back to your player. Have a look in the Knowledge Base
HERE for guides on how to do this.