Anyone else have problems with prox. sensor (iP5)

[Divit57]

My iPhone 5 screen (during calls) keeps turning on like I pulled it away from my face but I didn't. Which is bad because my face touches where the mute button is so I keep having to invite myself. Anyone else having this issue? Also there is lots of dust under my screen. If I took the time to count the little specks it would be probably close to 25 pieces of dust. Small but annoying knowing they're there.