Movistar Argentina is working ok on AOKP with the attached build.prop which was posted by mikeymike75 some pages ago.
I changed the default network type to 4 then rebooted.
Then go to Wireless and network setttings, and:
Enable alt OEM telephony code OFF
Enable alternate getIMSI code OFF
Enable World Phone settings. OFF
Set Enable GSM Signal Strength ON.
Reboot and set correct APN for working HSDPA
Thanks a bunch.