No, it will still restart if you continue holding after the screen shot. What you can not do however is restart without also taking a screen shot, something slightly irritating, but not a deal killer IMHO. I personally I'd rather not have a bunch of screen shots simply because I needed to do some reboots, but can live with having to delete them.
Sent from my DROID RAZR MAXX using Xparent ICS Tapatalk 2 with Google voice to text translation. Please excuse any minor spelling, punctuation, capitalization or grammatical errors.