Did you install any plugins today?
I re-installed slim jetpack after I saw that the menu option was not working when I pulled my site up on my IPhone. It originally worked great when I installed the plug-in a few weeks ago and then yesterday (Thursday) is when I noticed it not working anymore. Yesterday (Thursday) is when I un-installed and re-installed it hoping that would fix the issue. I had a few other friends try to access it on their iphones and ran into the same problem…so I know it is not an issue with the iphone.
I need to figure this out asap as I use this as a tool to show my artwork. Thanks so much!