The files are on my hard disk, I'm not working across a network. I've just set up a quick Auto Save and Auto Backup so hopefully when it happens next it won't take so long to put right! Thanks for advice.
I am using OSX 10.4.6 and Quark 6.5 and keep getting this error too many times. I get the error on opening a saved file. Every time I get the message the file size has gone to Zero KB. Anybody any other suggestions/preventions other than Markztools? Recreating jobs is driving me mad!