I did this with my RAZR.
Before starting I would make sure that ALL your contacts are saved to the SIM card on your RAZR. Go to Phonebook>Menu>Copy>All to SIM>Merge
Now go into your phonebook again on the RAZR.
Hit the menu key(the center one in the top row on your phone)
Scroll to Copy and select it.
Scroll to All to Phone and select.
Select Overwrite since all your contacts are now written to the SIM. If you select merge you will get duplicates due to a limitation the Symbian OS on the phone.
The overwrite will take 10 to 15 minutes depending on how many contacts you have.
This will store all your contacts in the phones memory which is the only thing that is read during a sync operation with your Mac.
The sim is not read at all during a sync.
When you go to sync it with your Mac make sure you tell it to merge or it will erase all the contacts in the phone(but not the sim) and replace them with contacts from your Mac.
If you can't get this to work let me know. I have another method that takes a little more work.
Dave McGraw
Macbook,Powerbook,iPod,iPhone Mac OS X (10.4.10)