Recovered deleted backup files but can't use them

[sputnikmeister]

I upgraded an iPhone 2G from 2.2.1 to 3.0 using these instructions for Windows;

Unlock iPhone 2G OS 3.0 7A341 Final Version | Featured

Things went fine, but when I set up the phone as a new device, it deleted my old backup in iTunes. I managed to get these files back - from Apple Computer/MobileSync/Backup/ada6d1325e64 - using recovery tools, but when I delete the new backup files and drop in the old ones iTunes refuses to see that there's a backup available.

Is there a trick to this? I think the backup was made with an early version of iTunes, before I upgraded to 8.2 to installed 3.0 on the phone. Whether the phone is running 2.0.2 (a downgrade as part of the upgrade) or 3.0, iTunes won't acknowledge those files as a backup when I right click on the phone or when I look in preferences under devices.

Any suggestions? To make matters worse, it's my wife's phone and my WAF is set to plunge in the morning if I can't fix it.

I've almost given up on this, I suspect I can recover things like photos using extraction tools but I'll never be able to restore her SMS history to the phone, for example. I'm keeping those backup files, just in case someone can tell me how to get them to work.

The big problem now that I need to do exactly the same upgrade again for a friend who has the same phone. She uses it for work, so she can't afford for me to lose her backup. How can I ensure it doesn't happen again (I still don't know exactly what I did wrong the first time). Is there a way to safely export an iPhone backup from iTunes and then import it after the upgrade is finished?