[Q] Upgrading to ICS makes touchscreen not to work topic

I have a strange problem, when i upgrade to ICS (v30a/b/v28a) my touchscreen wont work, i tried to factory reset and tried to flash with xloader but nothing.The screen gets touch as the menu buttons lights if i touch the screen but i can't use the menu buttons and the touch neither. But if i downgrade back to GB its become working again.

Maybe this happens becouse i have a replacement digitizer or becouse it was locked to t-mobile(unlocked now)?