Some Contacts not showing up but are still stored in iPhone 4
Had a similar problem after doing a restore on my iPhone 4. I just tried something that seemed to work. Went to contacts and selected groups. Selected Hide All Contacts and immediately selected Show All Contacts again. The missing contacts re-appeared along with duplicate entries for the one's I recreated.
I just went to 'Settings'> 'Mail, Contacts, Calendars'> scroll down to 'Contacts> select 'Import SIM Contacts'. All my contacts were restored to my Address Book.