Cant extract that itunes backup to get just the messages using itunes.
The restore from back up doesn't restore any phone software though, only data so do a factory restore, dont restore from back up and test it with one or two tracks, then you know where the issue is.
BUT,
If you look:
Windows XP:
%APPDATA% = C:\Documents and Settings\[your username]\Application Data\
Windows Vista:
%APPDATA% = C:\Users\[your username]\AppData\Roaming
Windows 7:
C:\Users\user\AppData\Roaming\Apple Computer\MobileSync\Backup
There will be a folder with a randomly generated name that's just a bunch of hex characters i.e 3d0d7e5fb2ce288813306e4d4636395e047a3d28
Inside that folder there are some files with the extension .mddata or .mdbackup, Thats where your text messages are stored.
I found this info on google ages ago, i extracted the data into a pdf file for a client using a website. Didn't put them back onto the restored phone though.
