Time machine seeing cloned drive as a new drive??

I recently cloned my hard drive and installed the new drive. When I hooked up my external drive to do a backup with time machine, it began backing up all 60 gigs, instead of just the small bits of new data that had since been added to the new hard drive. Is there some way to make time machine do a "update backup" like it always has?
Thanks!

Not really .... TM has detected the cloned drive as a new one ( that had not been backed up before ) hence it starts from scratch ... better be safe than sorry.

Cheers ... McBie

Yes, that's correct. Part of how TM identifies one drive from another is a device identifier. So, new device must therefore equal new drive to back up.

I would say to just let it start over if you're comfortable that everything of value was successfully transferred from the old clone. Just let it work overnight.

Thanks for the reply guys. I've heard of software that looks for duplicates on your computer. Anyone know if you can use them on an external backup drive? I'd really like to avoid having 60 gigs of the duplicates...that would put me close to filling the drive I might just need to bite the bullet on a new external drive. Any ideas?

This thread contains an explanation of what is probably happening as well as some possible fixes. Chas_m is correct about the likely source of the problem. A few workarounds are presented in the thread but I have not tried them.
10.5: Reconnect Time Machine backup after drive swap - Mac OS X Hints