Hi Tim as others have told you too: You have to backup on different non rewritable mediums to be "quite" safe. Whenever you connect and use your external hard disk, your data is at risk and a (yet unknown) virus could do it's damage.
You see Tim, **valid** and useful backup strategies have been invented already! There is no need to argue about that over and over for me. Back to Pentax topics greetings Markus >>2. And that it's rather unlikely to get viruses at a disconnected drive. >>(Perhaps Marcus can fill me in here.) Let me add that I run a pretty tight >>antivirus regime. >> >