Hmmm...
Well I was able to synchronise my contacts from PC to Phone after doing following your advices Abi.
Then I upgraded the Firmware Over The AIr (FOTA) from v4.xx to v.6.01 (Nokia 208).
Then I couldn't delete contacts on the phone & Sim Card (to then do a clean sync) so I did it from the phone ... Not so clever, I should have tried to sync again first.
Because now Nokia Suite doesn't want to sync anymore... Saying "A problem [...]. A contact application is open on you device. Close the application and try again. Error code: 80700000 8d5e000a"
The thing is I don't have any particular contact app open, or I have no idea of what it can be (In any case I'm on my phone's "desktop"/home screen)
I tried to uninstall Nokia Suite 3.54 and Connectivity driver, tried with 3.6, 3.8, and followed Abi's installation guide again... Same!
What is strange is that Nokia Suite can nevertheless read SMS/Photos/Video on my phone...
Any idea (all my contacts are gone :smileysad:)?