Rooting the phone using Odin and insecure ROM was easy.
I tried to use the RomManager app to flash ClockworkModRecovery. I rebooted into ClockworkModRecovery and then attempted to install the Cyanogenmod 7.1 zip I had downloaded and copied to the SDCard. I got errors like "Invalid whole-file signature"
I then used Odin to flash GT-I9100_ClockworkMod-Recovery_126.96.36.199.tar. There is a guide that mentions using this, although I did not actually find this guide at the time: http://www.thegeeksc...galaxy-ii-phone
I rebooted into ClockworkModRecovery and then attempted to install the Cyanogenmod 7.1 zip. This time, it seemed to install far too quickly. I rebooted and sure enough it failed to boot.
When I rebooted into ClockworkModRecovery I found it had been upgraded from 188.8.131.52 to 5.2.6 or something. I attempted to install the Cyanogenmod 7.1 zip again. A proper installation bar appeared. I also installed the Google apps zip.
I rebooted. Finally Cyanogenmod loaded normally.
I used Titaniumbackup to restore everything. Cyanogenmod then became unstable with crashes in Android core components.
I decided to revert to stock rom to save my contacts etc. and tried to install it using Odin. It would not boot. (I tried several times)
I reflashed Cyanogenmod again and found a way to extract my contacts from the Kies backup file to get them on to the phone. I lost some but never mind.
I had problems with the market - it would not download some of my apps (saved in my Google profile). I kept deleting the market cache over and over and gradually it allowed me to (re)install my apps.
I had problems with the phone shutting down when showing 66% power, so I recalibrated the battery which seemed to resolve it.
I've now replaced the ADW launcher with Zeam, dialler with DiallerOne, sms messager with Go SMS Pro, keyboard with Go Keyboard, browser with Dolphin Browser HD. Installed AdAway ad blocker, Droidtools, MyPhoneExplorer client. I turned off the lock screen as I just want to use the old pattern unlock one.
Finally, Cyanogenmod rules. But it has to rule since it looks like I cannot go back to stock roms with Odin any more.
Edited by mcarans, 20 October 2011 - 09:10 AM.