I've been having an issue with the Otterbox Defender Case I purchased direct from Otterbox. Power button in the case will sleep and wake the phone, but to turn it on or off is not working. I'm trying to work with Otterbox to resolve this issue. I liked the Otterbox case that I used on my S II Skyrocket and had none of these issues. Hopefully the matter will be resolved soon. I'll update as things progress.