I posted this in here because i can't post in Development because i'm a noob (less than 10 posts).
The update 8107 is already available for Samsung Focus i917R (Rogers) so what i did are the next steps:
1.- Jailbroke my AT&T Handset.
2.- Installed WP7 Root Tools from this site.
3.- Changed the values ATT-US to ROG-CA using the WP7 Root Tools on the next path:
Local Machine\System\Platform\DeviceTargetingInfo\Mobile Operator
After the update i restored to ATT-US just in case, my device is Unlocked to any GSM and is working great, even the ear speaker sounds better (IMO) still is Jailbroken and is on 8107.
Picture on the 4th post