I upgraded to 12625 not a problem, as soon as i ran dashlaunch for the 12625 i started getting problem. My games would not boot from disk or from HDD. The xbox kept freezing on startup at the logo. I couldnt even get on the dashboard. I flashed back to my 12611 and it was the same. It has took me two days to figure out why. I have formated my HDD three times.
If i flash back to 12611 and change dashlaunch for the previous 12611 relese everything works fine. I dont know why this happens but it has for me. I cant even install the system update for the avatar's on 12625 but if i flash to 12611 and then try the 12611 avatar update it works.
It has been a nightmare to figure this out, but as soon as dashlaunch 12625 is on my hdd all hell braks loose and nothing will work.
Just wanted to let people know what happend to me just incase they are having the same problem.
I have a falcon Jtag