How do I un-jailbreak and restore app data

[Nitsson]

I have a 3GS with iOS 4.3.3, jailbroken with jailbreakme. As I have recently upgraded to a flashy new Samsung Galaxy SII (great phone, though I miss many clever iOS features, not to mention the apps) my girlfriend has inherited the 3GS... half the apps are hers anyway.

Now, she doesn't need any jailbreak functionality (particularly since iOS 5 is around the corner), and isn't too impressed by the occasional springboard crash, so I'd like to restore to vanilla iOS. Tried upgrading iOS 4.3.5 but iTunes gave me an 'unknown error', presumably relating to the jailbreak. I guess I can restore in recovery mode and restore data from the iTunes backup, but will this actually restore the app data? It is important that we keep this.

Many thanks.

[jima6636]

anything you sync will be saved and what error is it giving you ? that usually helps when trying to find a solution

[Mes]

After a firmware restore, iTunes will offer to 'restore from the last backup' or set up as new phone. Sync'ing will take care of the rest. Cydia apps & tweaks will be gone.

[Nitsson]

After a firmware restore, iTunes will offer to 'restore from the last backup' or set up as new phone. Sync'ing will take care of the rest. Cydia apps & tweaks will be gone.

Yup, figured out that was the way - thanks for confirming.