White box on screen

Hi

I have a Dell XPS L502X running Windows 7.

I have read about this white box that appears on top-left corner of the screen, but my white box is kind of different... it appears outside the laptop screen, so you can only see it when using an external monitor, as you can see in the image below. I use a lot the external monitor, so is kind of annoying.

I have installed Dell DataSafe Local Backup, but is not running at startup (at least the tray icon is not there) because some posts pointed that the problem was related to DBRM process.

I am pretty sure that this issue is software related, because after the welcome screen, I saw the screen without the white box for a few seconds.

The issue have been there since the first time I boot up the laptop.

Any ideas?

Thanks.