I’ve tried completely uninstalling and reinstalling the plugin, and it’s still giving me the error. Though for some reason, it’s not just Jetpack. I get the same error when I try to go to the Updates page, and when I try to change the mobile theme in WPTouch Pro.
EDIT: I just posted over at the Jetpack forum too, so hopefully they have a way to fix it also. Though since it isn’t just Jetpack that is acting up, I hope someone here can help too. Thanks for the link though.