Slackware :: No Eth/sound/agpgart After Recovery From Backups?

I wanted to clone a system (running slackware 12.1) so I created a tar file with all the directories from the original system, skipping over dev, mnt, proc, tmp and home. On the target system, after dumping the directories and running lilo (after using chroot to the mounted partition), the system booted and worked almost fine. The only problem is that the network card, sound card are not detected, and /dev/agpgart is not recognized by X. Everything else (usb controllers, PCMCIA, etc) works.

I had to create /proc on the target filesystem, and copy (with -R) /dev from the live cd (2005 gentoo based System Rescue CD) to the target filesystem. Are some files missing or maybe permissions are not set correctly? This is the second time I'm doing this and I'm missing something, but the first time it worked flawlessly (though it was one year ago, so I can't remember the details ) If anyone tried to clone a system the same way, please share any ideas (or any other way to clone one system to another (the systems differ from every point, so dumping the whole partition will not work), since a full reinstall takes too much time)