Q: iTunes won't backup iPhone

When I connect my iPhone to iTunes via my usb it normally automatically syncs and backs up my iPhone. This evening my phone was not taking photos correctly and it then switched itself off. Following that it rebooted and my photos were 'restoring' 3 times.

Now when I try to plug my iPhone into iTunes it goes through the sync and back-up process only to tell me that 'iTunes could not back up the iPhone "Lydia's iPhone" because the backup was corrupt or not compatible with the iPhone.

Does anyone have a solution? I don't really want to delete old backups in case it still won't back up and I'm left with nothing. Please help if you can - I've had so many problems with this phone and I can't believe I'm on this forum yet again!