Just noticed a grey section on my screen that doesn't wash away and it doesn't show in a screen-print.

It looks like, and is about the same size as, a back to front bold 12 point apostrophe.

Could this be a "dead pixel" that I've heard about? Anything I can do to fix it?

 

yes sounds like dead pixel. No you can't do anything about it unless its under warranty and even then they might not replace if its only one pixel.

 

They wont do anything for 1 pixel, something to do with acceptable amounts or something. There are programs that you can try to fix it, but no idea how successful they are.

Google dead pixel and you'll get loads of results

 

A program to fix dead pixels? I wonder what that could do. I'll go check.