White Circle on screen behind where the Dell Logo Is

 System: XPSM1330 

Hi,

I can't seem to find any threads on this so I'll just ask now.

I had a white circle (and a dead pixel or defect, never sure about these things), on the screen which shows up generally behind where the dell logo is on the lid. I don't recall if it was originally there, or if it has been caused by my use of the laptop. Anyway, I called Dell to ask to send a technician to replace the screen and they did - problem solved. There isn't a white circle on the screen anymore...

However, I'm worried that it may have been caused by my use of the laptop, in which case, it'll show up again. I tend to stick the laptop (with it's protective case by Dell) in my backpack, but that also has folders filled with papers and books so it ends up being pretty tight for everything. I do this everyday as I tend to study anywhere besides my apartment.

I saw while the guy was replacing my screen that there's a support ring behind the logo and was wondering if the pressure in my backpack was causing it --or--if it was simply a defect in the screen itself. If it's the former, I guess I'll have to find myself a nice laptop carrying case that's seperate from the backpack (or not carry so much), if it's the latter, then I guess I wouldn't have to worry.

But my main question really is: what caused that circle in the first place?

Thanks for any help!