I can't enable iCloud backup on my phone My iCloud backup is currently off.  So I go into Settings/iCloud/Backup and switch the iCloud backup slider to on.  

It comes up with warning stating that the phone will no longer back up to my computer automatically when I sync with iTunes.  I say Ok.  Then the phone thinks for 2 seconds and comes up with an error saying iCloud Backup Failed, `There was a problem enablling iCloud Backup'.

Why can't I enable backup?
You can perform the same function through iTunes on your Mac. Just plug it in, go into the iPhone's settings, and set it up from there. May have better results.