[Galaxy S II Q&A, Help & Troubleshooting] devid801:
u can keep ur old id or can change to new id, its up to you as some developers use android id as a way to ensure you're you in some way that isn't as douchey as asking for your hardware id numbers like IMEI or MEID. It's also the way Google recommends to developers for determining who is who for whatever reason. It normally gets reset every time you flash a new ROM or go back to stock.

if u will change ur id ur phone will restart and ur device will have new id although u can keep ur old id too ... no issues there.

Ten Easy Steps for TiBu success:

1. Open TiBu.

2. Menu > Preferences > App processing mode > AUTO Direct (Should be this by default anyway)

3. Create your backup: Hit the Batch button to the top-right on your screen (the one with a checkmark). Hit “Backup all user apps” and click the green checkmark up top on the next screen. When getting ready for future wipes and ROM flashes, you are going to scroll down and just hit “Backup new user apps & newer app versions”, followed by “Redo backups for modified data”... This will update all those saved games and other info that has changed since the last time you backed it up. Do not backup or restore system data.

Note: While not required.. its a great idea to periodically move all of your backups to your computer for safekeeping. When connecting to your computer you will find a /TitaniumBackup directory on your internal storage. Go ahead and just copy the entire folder over to a safe spot on your computer, and update it from time to time. You never know when you that might come in handy!

4. TiBu now lets you backup and restore your call logs, SMS messages, and browser bookmarks (stock browser only).. How sweet is that?! On the main screen hit Menu > Backup data to XML and choose what you would like to backup if you please.

5. Now we're going to make an update.zip.. This is an awesome feature that gives you a file to flash after your ROM, so that when you boot up you will have TiBu already installed and ready to restore all your apps! Menu > Create "update.zip". The only thing you want to change here is under "Titanium Backup will be installed as:" Select "System application". You can change the name of the output file if you like, I just leave it as update.zip for simplicity. Hit your green checkmark up top and you are good to go.

TIP: Remember to create a new update.zip before your next ROM flash if TiBu has been updated at all since then.. which it probably has if its been a while, the developer updates things a lot!

6. Boot to recovery.. flash your ROM and Gapps (if needed). Now Mount the System, then install the TiBu update.zip we just created. Now... reboot.

7. Skip the initial device setup screen. This can be done by quickly tapping the top-left, top-right, bottom-right, and bottom-left corners of the screen in that order. Or you can just skip through everything without entering your Google account info.

8. Launch TiBu and do Batch > Restore missing apps with data. Now here's the important part.. hit Deselect all. Go through the list and manually select the apps you want to restore with data. You can do it safely for MOST user apps: games, utility apps, etc. But do NOT restore data to any Google apps, and try to avoid it for any apps which actively sync often or create accounts in your phone setup. Can you get away with some of these things sometimes? Maybe.. but just don't take the risk. Restoring any bad data you shouldn't could mean you'll have to re-wipe and start all over again. Once you're done selecting, hit the green checkmark to start the restore.

9. Now run through that last step again... This time after hitting Deselect all, hit App only. Now you can select the apps you are going to restore without data. You can do this for just about anything, including your google apps. Its the same as installing them normally.. TiBu will just do it for you in one quick batch job. Afterwards you can do a Menu > Restore data from XML and restore any the call logs and SMS data we backed up earlier as well.

10. Reboot. Go to Settings > Accounts > Add your Google account and set up your phone again. You can take it from here

After I boot from a clean flash I open TiBu and the first thing it does is ask if I want to restore the previous ID...