Backup

Nothing in either of your Macs would automatically format a disk without informing you first and presenting you with the option of cancelling said action. Yes, you can use a single disk to back up two Macs, given that they do not share a common computer name. http://forums.macrumors.com/showthread.php?t=405606 Be aware that if you have a multi-interface external drive...

install 10.4 on the one running 10.5 to preserve all your data. Just to be on the safe side you should have a backup if your data is that important to you. ...

It seems odd nobody has mentioned this... Just boot from your Leopard Install CD. Go to Utilities > Restore System from Backup.

The more you write, the clearer it becomes that you have convinced yourself that you have a problem. Now you are looking for confirmation. My advice to you is to get a move on. The wild geese are ready to fly south for the Winter.

Thanks for your replys, DeltaMac, Of course I expect most ppl to think I'm some paranoid fool. I ran Tiger on this machine for 4 years with no firewall and never had a problem or suspected one. I am not a paranoid person and am very familiar with the GUI side of Mac OS X. I know something is up, but I don't know enough about it to say what exactly is going on. I don't...

That would likely stay in place, because the backup that you restored from would keep record of the volumes used for your time machine backup. Does that help you at all? ...

One other Windows & oddity that bugs me. The Boot Camp idea djackmac had it it worked for a whole disk, thank you. :) The oddity is on my two external Firewire disks (I use one for Time Machine and the other for a Carbon copy daily clone backup) something strange happened to them upon going back into Snow Leopard I found those two Firewire 800 disks were unreadable. After...

If I were to recommend someone go this route I'd just make sure they have a good backup they can revert to. ...

To have a fully bootable external (OS X will boot from and external drive) then you need to "clone" your OS X drive. A freeware application that will do this for is Carbon Copy Cloner. A shareware application that is for people you know little about how OS X works (rsync) use Super Duper. Now I see the word duper and think since CCC already does all this for free why would...

In order to use Migration Assistant, would the external drive have to be connect by firewire? Could I use a USB disk?