I'm getting somewhere with this now. Indeed, the Boot-Repair did fix my Grub2 and I am able to boot into Ubuntu on /sda3. I ended up using the Ubuntu Secure Remix iso for this, and it was pretty straightforward.
I have done most of the commands you suggested, except this one:
I'm afraid you've lost me a little here on this (above).
more /var/cache/debconf/config.dat | grep /dev/disk
UUID in grub, fstab & maybe a few other places?
The output of "more /var/cache/debconf/config.dat | grep /dev/disk" produces:
What, if anything, should I do with this information? What 'other places' could there be where I might need to update the UUIDs? Presumably the UUID update as been performed correctly in Grub2, else I would not be able to boot? Correct???
RAW_CHOICES = /dev/disk/by-id/ata-Samsung_SSD_840_Series_S14GNEACA38632P, /dev/disk/by-id/ata-Samsung_SSD_840_Series_S14GNEACA38632P-part3
I edited my fstab in /etc/fstab and the only UUID (as checked with "sudo blkid -o list") that was incorrect was the swap partition on /sda2. I guess this is why when I look in System Monitor, my tux box reports that the swap is "unavailable". We will see if this has become available when I have rebooted - which, incidentaly, is lightnig quick now with this SSD installed!
The other issue I have now is that Win7 won't boot, claiming that the MBR is broken and that I should put my install CD in to fix it. I am yet to try this, because I want my tuxbox working great first. I only use Win7 when I need to do work in Office etc. I'd prefer a solution from within Ubuntu if possible to fixing my Win7 partition on /sda1. I just have a sneaky feeling that running the MS solution to fix Win7 will break my beloved Ubuntu!!
Thanks for your help with this so far...it's been really great and informative. I've learned so much, with much much more to learn in future.
== Update ==
Yes, the UUID change for the swap on /sda2 did fix it. The system monitor now shows my swap as active.