Backup drive does not show up as startup option

[t3rockhall]

Originally Posted by dnanian

Does the drie show up as a boot drive choice in the startup disk preference pane?

No (I noted that in my OP). Just the internal and a "network drive (with a question mark)"

If it matters, the G4 iMac is running 10.5.8. I also reset the PRAM and the Open Firmware, and ran OnyX.

I also downloaded a new copy of SD! and replaced the one on the HD.

I hadn't previously tried to use the backup as a startup (not for several years, anyway), but this came up when I went to back up the HD and a dialog box came up for a new version. When I said OK to install, the installation crashed, gave me a red dialog box. It wasn't the same after that, if this information helps.