Unhappy ViperXL2.0.0 and WIFI

Hii all i have At&t HTC One x + , which is Bootloader and country Unlocked. Well the problem i was facing was that whenever i used to put local sim in the cellphone other than at&t my wifi would not connect. Then some really fine members of XDA helped me with this problem and i was able to use my local sim along with viperxl 2.0.0 and WIFI. This was achieved by using Market Unlocker and Wificodes together. But i would like to know y is this happening? The wifi only works when the wifi Country code is on "US".
My Radio is and HBoot is is i downgrade my radio to _1.09.55.17 will this help? And is there any solution to this problem?