Im not sure have you forgotten or you just dont know how... but you havent scaled the wallpaper to fit the monitor at all... if you dont know how to do it, send this PSD to me and I fix it!
After reading your comment I took a moment to look carefully at my preview, and found the problem you're talking about (well, I think I did). I just pasted the wallpaper on top of the monitor layers, used Transform to scaled it down to fit in the monitor. And kinda forgot to clip the wallpaper to the screen... It is because of that?
Wow, your version is totally dope man! Can I use it as the new preview for this wallpaper? I'm too lazy to make a new one, plus your version looks wayyy better than the one I made xD