There is an issue with xamarin studio ios and storyboard designer. I have two identical mac mini machines. One the xamarin designer opens correct and the other it just hangs and spins. You have to force xamarin studio closed when closing xamarin studio after this happens. It never seems to get past starting full reload. I have latest xamarin and xcode also this xamarin using xcode designer works.
[2014-03-10 20:16:00.8] INFO: ENTERING sandbox: com.xamarin.MTHosting.2e55361 [2014-03-10 20:16:00.8] INFO: Starting simulator at: '/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.1.sdk' [2014-03-10 20:16:00.8] INFO: ENTERING sandbox: com.xamarin.MTHosting.2e55361 [2014-03-10 20:16:07.1] INFO: Starting full reload...