All official firmwares for Géant GN-CX 1200 mod are listed there:
but I'm not able to download anything from http://www.gulfup.com (I made a PING, not able to reach)
Could you please mirror them? I only have v3535 but when I try to update this bin with USB it stop before the end.
At least upload the previous one: V3531_GPRS_GEANT_GN-CX1200_LED_RD.bin
Thanks a lot in advance.