I leave my images as referenced files, and I back them up routinely to two external hard drives. I also back up my aperture vault to keep a track of changes. However, I have a weird problem that I can't find a solution anywhere. The last time I tried to recover my Aperture library (after doing an Erase and Install), when I tried to use the Vault back-up, it couldn't find the files because their location was on my (now deleted) hard disk. I had put the files back in home>pictures, but Aperture seemed unable to recognise them because this was a 'new' home>pictures. So the last time I did a re-install I ended up exporting all my projects as hi-res TIFFS and re-importing from scratch... far from ideal. Can anyone help me here?? Cheers, K.