Ok...sorry for the delayed answer here, but I didn't have a chance to work on this til just now.
I first went through the bios, and checked the settings between the first drive (80GB, working) and the second drive (500GB, not working.) They are identical.
Next, I booted the livecd Gentoo 2006.1, and found the same problem, no second hard drive. After that, I found that I didn't have another live cd, so i downloaded the latest Fedora Core 7 install.
I let the install begin, and got to the partitioning section, and it
was able to see the second hard drive. After some further research, I found that Debian Etch runs the 2.6.18 kernel, which has some issues with some SATA drives. After finding that, I am now working to compile the stock 2.6.21.5 kernel, following the directions at
http://www.howtoforge.com/kernel_com...on_debian_etch . I'll post if this works or not, and if anybody has other directions for compiling a kernel that might be better, I'm all ears.
If this doesn't work, I might have to switch distros and just use Fedora, since it detected the drive, no problem. Thanks for the advice so far!!!