Nokia :: Lost Contacts After Backup To SD Card

I recently replaced my n85 as it was malfunctioning. I backed up the phone memory to SD card. On restoring this to my new phone, the contacts doesn't seem to have been restored. On entering the phone book, it says "contacts from selected memories not available". It seems strange as, upon receiving calls/messages, my phone knows who they are from (ie. the name of the contact comes up rather than the number). It seems the contacts are somewhere in the phone but it just won'r let me see them.