iCloud disabled in settings on iPad

When I installed the iOS 5 on my iPad 2, I skipped the activation of iCloud. Now I need to tie the iPad to iCloud. In the settings, both twitter and iCloud are gone and can't be activated. My mail settings are grayed out as well as is the fetch/push setting. And I can not edit any of my account settings. Try resetting the device with no success.How to fix the iCloud issue* Tap Setting > General >