I have small white boxes going all the way across the bottom of the screen, has anyone else encountered this? (iPhone 5)

First thing to try is to reset your device. Press and hold the Home and Sleep buttons simultaneously ignoring the red slider should one appear until the Apple logo appears. Let go of the buttons and let the device restart. See if that fixes your problem.

If that didn't fix the problem definitely Make an appointment at an Apple Store to have your device examined by a technician. Or contact Apple Support.

I had this problem after re-assembling my phone after replacing a bad rear camera (thanks ebay and youtube!!!). turns out it was a loose ribbon cable from the display to the motherboard. I popped the thing back open and made sure all 3 ribbon cables that connect the front screen to the motherboard were secure. sure enough, one of them was loose and once i snapped it back into place it was fixed. if you look on youtube for iphone 5 screen replacement tutorial you will see the 3 ribbon cables i am talking about and how to access them. it does require a few tools to get inside the iphone. It is not rocket science but i could see how most people would be afraid to attempt opening up the iphone. my advice is this...hey its broken anyway...if you fix it you can put off buying a new phone longer, just take your time, do it slowly and carefully. Also a cell phone shop that does screen repair can do it, just know that the more naive you seem to them on the subject the more they will charge.

after a quick search it looks like it could be a display issue due to a lose connection, which could need replacing/fixing:

https://discussions.apple.com/thread/4361737?start=0&tstart=0

when you say reset do you mean factory restore? or just turning it off?

Hi did you manage to get to the bottom of this? Iv got the same problem.

Thanks