Whenever I boot my computer, the Mac OS Finder asks me if I want to initialize the disk or partition onto which I installed the BeOS. Why does the Mac OS keep trying to initialize (and therefore destroy) my BeOS hard drive?

If you prefer to fix this manually, before you accidentally destroy your BeOS disk, you need to change a hidden setting for the volume to be correct. Then the Mac OS won't look at the drive (or partition) at boot time and (helpfully?) offer to blow your BeOS drive away.

To do this, you need to use your hard disk formatter to change the "auto-mount" setting (generally called "auto-mount" or "mount at startup" or something like that) to be OFF (unchecked). If you don't know how to do this, check the users guide for your formatter software for details.