Hi,
I have tried your solution but unfortunately it has not brought any improvements.
I live in a quite rural area, so no pertubation from the neighboor...
Anyway I want to thank you for helping me but I'm getting really tempted to bring it back to the reseller as I have the feeling that the problem is hardware (maybe problem of low alimentation of the card?). But I do not want to open it myself by fear of removing the warranty.
But if you have any more advice, I willl gladly take it and try.
Best regards,
Baptiste