zabreen wrote:
1) was old backup file deleted and overwritten with "new" backed up data?
iTunes keeps 1 iPhone back up.
It updates or deletes the old one if you do a new one.
When you back up again, then yes it will erase the old back up.
So if you renamed your iPhone as per the old name, and then hit Backup, not restore, then chances are your back up is gone.
Also Contacts are not backup in the back up, but rather in the addressbook of the computer;
http://support.apple.com/kb/HT1386
That explained how it will first ask you what to sync address book data too.
If the addressbook data was not sync to your computer, then it will not be there.
Photos and Music I believe are the same.
iTunes has the copies of your music.
And your choice of photo app has the back up of your photos.
2) why can't I restore from old backup file ?
I am not sure.
Here is where iTunes keeps back ups:
Mac OS: ~/Library/Application Support/MobileSync/Backup
Windows XP: %AppData%\Apple Computer\MobileSync\Backup
Windows Vista: %AppData%\Roaming\Apple Computer\MobileSync\Backup
Windows 7: %AppData%\Roaming\Apple Computer\MobileSync\Backup
Have a look if there is a large files/back up there
3) is there a way to restore the info initially backed up in the old backup file?
Not unless you have a back up of the back up; by that I mean a back up of your computer.
It is good to have a full back up of your computer, and in that case you can restore the computer back up (or more specifically the iPhone back up in the computer back up) and restore.
I use Time Machine on a small USB2 1Tb drive.
It works great for exactly these kinds of problems.