To handle the large amount of data that I maintain I have 4 backup jobs. They operate as a set and any change to one usually requires changes to others.
One differential job runs daily and backs up all user data that has changed but does not clear the archive bit.
The second main data job runs weekly and backs up the most important, most volatile data and clears the archive bit.
The third and forth minor data jobs run monthly and backup more static data also clearing the archive bit.
Once a month the latest zipped files are copied to DVD for permanent storage off-site.
The problem occurs when I am making changes to these jobs as I tune them. I open the first job, tweek it and save it. Then move to the second job and do the same. After doing this a few times, ZipBackup will not open any more job files. The OPEN command goes through the motions of opening the selection window and making the selection, but the heading and parameters remain stuck at the last job modified. The job file is not actualy opened at all.
Sometimes fully closing and reopening the ZipBackup program helps, but this cannot be counted on.