Re-Root to 2.2

Did you sync your contacts with google? If so, it will put them all back after you flash your rom (even if you wipe all data/cache).

 

If you sync'd contacts with google, then I don't understand why your contacts wouldn't be put back on your phone when you install a new rom.

Also you are not understanding the terminology. You only root your phone once (you gain root access, which allows you to access the 'root' files which are the system files). After that you can install custom roms with different versions of the Android operating system. You don't 're-root'. Please tell me you are making backups of your roms. Especially the stock rom.

Something that might cause you to not sync is that you can disable syncing. Some people disable it to save battery. The power control widget has two arrows in a circle to disable/enable syncing. Or you can to go settings>accounts&sync.

Maybe I'm not understanding your problem since this is basic stuff. I'm not sure if you are a beginner or not. It sounds like it since you are not even backing up your apps or anything. Don't take that as an insult though; everyone has to start somewhere.