Hi guys, I'm currently using iPhone 3GS on tethered Jailbreak by Blackra1N. Firmware is 3.1.2, SG set. I'm using DiGi line.

According to many gurus here, it's best that I restore the iPhone instead of updating to avoid possible errors.

But I'm a paranoid and I don't wanna lose my SMS, Contacts and various setting when I restore, so below, I have highlighted the steps that I'm going to take. Any kind gurus here, if you notice anything wrong in the steps I've mentioned, please point out for me. Thanks.

1) 1st, I will back up my iPhone through iTunes by right-clicking on my iPhone device and choosing backup (Instructions in the first page says do a full backup, I'm not sure if this is right). (This should back up my SMS/MMS, Contacts, Call logs, Email and calendar settings)

Or alternatively, should I sync the iphone instead?

2) I will restore to iOS4 with the file downloaded from here
http://appldnld.apple.com.edgesuite.net/co...93_Restore.ipsw

3) Once iOS4 installation is complete, I will then right click on my iPhone from itunes and choose Restore from Backup (This should restore my SMS/MMS, Contacts, Call logs, Email and calendar settings)

4) Assuming I did a back up instead of sync, I would have to download all the apps purchased from App Store in iTunes and sync the over.

5) By synching, it will automatically sync the DiGi ipcc file over to the iphone and MMS + Internet Tethering will be available automatically (not sure if this is true, but I rmb reading this somewhere in this thread, please advise)

Please provide comments on any mistakes I've outline. also, when backing up, will it back up my Email and calendar settings (via exchaange server) rights?