constant out of sync errors

[StephenN]

We have been running retrospect 5.0238 on mac OS 9.22 sucessfully for many years but recently catalog out of sync errors have been cropping up. The catalog can be repaired sucessfully but will go out of sync almost immediately. We tried starting a new backup set and when this didn't help we reinstalled on a different machine with a different tape drive. This worked fine for a couple of days but we are now back in the same situation. I have tried repeated tape cleaning and driver reinstallation but as the problem seems independant of hardware and has only recently started occuring I suspect the cause lies outside the server itself. We have added a couple of intel macs to the network but as the errors are generated when backing up any machine I am at a loss. Any suguestions gratefully recieved.