Hey d3xp2pc, thanks for your answer,
There is no official stable cm11 for GN yet. I'll give the last nightly a try, to see if I still have the same problem.
I tried wiping everything, and flashed many times to try differents things, but still.
About gapps, sorry I just realized I wasn't clear in my previous post. My google contacts are correctly restored after sync, but some of my contacts are just stored in phone, and I couldn't get them back (it's like 4.3 and 4.4 contacts2.db and mmssms.db databases are not compatibles).
I haven't tried 0 day pa gapps, I used gapps-kk-20131208. I'll try the official one, but I don't think it will fix any of my problems (apn and sms), does it ?