En kompis hade själv samma problem för något halvår sedan. Han gjorde som på den här sidan:
Recovering lost iPhone data
"atomic hooligan" skriver:
I found a way to sort of mount the drive and consequently do a data recovery.
What i did was highlight the 'iphone-dump.img' and opened it with 'Disk Utility'. Inside of 'Disk Utility', I double-clicked the 'iphone-dump.img' icon and low and behold, it split into two drives, despite it giving me an 'Unable to attach 'iphone-dump.img' (no mountable file systems)' message at the same time.
I wasn't able to do much with it in 'Disk Utility' from there on, so I opened 'Data Rescue II' and it became available to scan as a 'Virtual Interface' called 'Apple read:write'. I performed a scan and was able to locate my missing photos. It took a while because there were several duplicates of older photos. I think this is because each time I've restored the phone from a backup, data has been placed in a different location on the hard drive. Therefore, it has not overwritten these very same photos that have been on most of my backups for some time.