I have an Express that I use in the States with AT&T gophone. I paid a guy at a shifty kiosk to unlock it for me so that I can use it temporarily in Canada with Virgin prepaid. It works with the new carrier, but now I can't toggle wifi on (it jumps back over to 'off'). The guy returned the phone to me, running 4.0.4. It now says "IP address: Unavailable," which I have to assume is the main issue with wifi. Mobile data works fine, but isn't ideal obviously. I've done a factory reset, talked to Samsung and ATT technical support for hours. I assume updating to 4.1.2 will help, but I tried this (using a version of Odin for OSX) and it didn't work. (I think may not have had the correct .tar?) Can someone tell me my options? Can I find 4.1.2 without wifi? Should I root? Can I root using my mac? Any advice is very much appreciated!