Safari 7 User Agent is set to “Custom” by default Ever since upgrading to Mavericks from Snow Leopard, Safari’s default User Agent is set to custom. Anybody has any idea why this happens? And how can I fix it?
I managed to fix it by deleting the CustomUserAgent string in the plist file.

defaults delete com.apple.Safari CustomUserAgent


But I still don’t understand how it got to be like that in the first place.