I used to have the same problem when upgrading to 10.10, to work around this is a bit of a pain but with the helpful Ubuntu-folks and tons of tutorials and step-by-step guide I got it to work.
Did you browse around other similar questions? Although it speaks about 10.04 and not 10.10, I think Blank screen on boot after upgrade from 9.04 to 10.04 with a toshiba tecra a2. Fix? or trather therein the link to the guide https://wiki.ubuntu.com/X/Bugs/Lucidi8xxFreezes might be what you are looking for aka get Ubuntu running to backup the missing data.
From the guide the following steps used to help me out:
From an existing installation:
Hold down Shift while booting to enter the GRUB menu.
Press e to edit.
Ctrl+x to boot.
I hope this helps for the moment.
The aforementioned guide has even instructions on how to make this change permanent -- OR you could even upgrade to Natty 11.04.
Is there a reason why you didn't upgrade to 11.04 where this particular problem does not exist anymore (as far as I know). Or then why 10.10 and not stick with 10.04 that is a LTS (Long Term Support)?
And a final word for future upgrades: I would suggest you first try out new releases on a computer using the Live-CD, most problems might show up there.
I hope this rough start with Ubuntu does not turn you away from it.