I've had two PNY cards fail to operate (corrupt files or total failure) lately, both being 32GB Class 10 "Professional" cards. It seems they cannot handle sub-zero temps, as they worked flawlessly up until we've experienced these deep freezes. I've had no problems with Sandisk SD cards, but have only used them for capturing images, not video. I'm going to try using some faster Sandisk cards to capture video.