I am having the exact same issue:
Replaced a hard drive in a macbook (with an appropriate SSD), that is now not recognized.
Formatted correctly (Journalled, GUID).
I can boot from the 10.6 install DVD
(the original install disks say they cannot install on this machine;
perhaps due to a firmware update at some point).
I can get to disk utility, but the internal hard disk does not appear.
Firewire drives appear. USB Drives appear. I know the new hard drive is good
because I tested it on a drive sled in a Mac Pro, and disk utility recognized it.
I am wondering what could be the issue (and am naturally loathe
to take it to a shop and drop $80 if there is a solution I can implement).
Using the Hardware Test on the original install disks did not work.
I will next try the network hardware test using ethernet and Option-D.
Suggestions?
Good Karma to you!