Backing Up after Jailbreak

[Squand]

Hey I have previously jailbroken my iphone 3G, and now just about to do it again. I was wondering whether once i jailbreak my iPhone on a windows computer, would i;

1. Lose all the data from my iphone, such as texts, contacts etc? and if i do lose them will i then be able to use iTunes to return them to my phone.

2. Be able to backup my iPhone once it has been jailbroken, using the iTunes backup feature, and then would it allow me to restore the files onto a formatted iPhone if i ever decided to un-jailbreak my phone again.

Thanks in advance

 

[dhlizard]

Hey I have previously jailbroken my iphone 3G, and now just about to do it again. I was wondering whether once i jailbreak my iPhone on a windows computer, would i;

1. Lose all the data from my iphone, such as texts, contacts etc? and if i do lose them will i then be able to use iTunes to return them to my phone.

2. Be able to backup my iPhone once it has been jailbroken, using the iTunes backup feature, and then would it allow me to restore the files onto a formatted iPhone if i ever decided to un-jailbreak my phone again.

Thanks in advance

Sync your phone before JB

After JB, sync back your stuff (not sure if texts will come back) but contacts, calendar, apps, music, movies, etc do come back.