OK - we have your clarification. You'll need to follow what I'm going to describe carefully for it to work. Not difficult or anything, just not what you would expect. Understand that this procedure will reset even more than a normal hard Factory Reset. The device will appear pretty much as it did out of the box in terms of settings -- re-doing all of your settings will be a bit of pain, but our last shot at a non-hardware answer to your problem. In essence, it kills the file that contains all of your personal configuration information.
From the main screen, select "Settings"
Use the left arrow to take you to the last page of options.
Select "Reset factory settings"
When the "No / Yes" options appear at the bottom of the first screen appear, press and hold in UPPER right corner (there aren't any buttons there, but press there anyway!)
The unit should shut itself down. Afterward, power it up normally.
Let us know how the unit behaves when you do this.