Lost data camera photos notes apps due to interrupted sync restore iPhone 3G

Hi. Ill try to summarise what has happened
Day 1:
iPhone 3g - O.S. 3.1.3 - So I decided to take the plunge and update to software to 4.2
Updated iTunes (& Safari & MobileMe)
Plugged into iTunes, Message read, I need to transfer purchases from my iPhone to iTunes.
Started to transfer purchases to iTunes, message on phone screen read, running out of memory on the phone, space needs to be freed up (or words to that effect).
No sync or back up taking place in iTunes but iPhone screen said, slide to cancel.
So I slide and cancel, unplug phone & start to delete some unwanted data (not the missing data).
Switch off computer, phone fine, all data still present.
Day 2:
iTunes on, phone plugged in, Message about software update cancelled as I knew I needed to transfer purchases to iTunes first.
However when phone was plugged in a screen appears stating the phone is synced with another computer and that restore is needed, to new or to the last backup (10.12.2010)
As I cannot do anything else with the phone I agree to restore to the last back up.
Phone runs through, restore, sync, backup stuff for about 2 hours eventually completes.
I eject the phone and notice that my apps state I have 18 updates so I decide to look at the other data.
Camera roll photos are missing, notes are too, updates have been reversed, texts are gone etc.
Obviously the phone has returned to the backup date (10.12.2010)
However a lot has happen between December & March (Birth of new baby for one). Is there anyway to find/restore the missing data? Im hoping that the files may not have been truly deleted and might be sitting in a folder somewhere
I havent synced or backed up since but I noticed 2 backup points are listed, December & yesterday.
Please help, you clever people.
Thanks in advance.
Kieran*
iPhone 3g Windows XP also use iMac Leopard