Hi dh321
First, update the firmware to this one.
All the Disk overwrite issues will stem from the jobs themselves. Here is the layman's terms for what is happening *as I understand it*(I am not a developer and do not write code at all, I have no access to those who do)
The printer by default is set to do a Disk overwrite after you do a job to remove any trace of the job from the memory/hard disks.
The problem is in how it checks that this was done.
You do a copy/scan/print, it RIPS/Processes, spits it out and deletes the job from memory, then checks that it got rid of it (Obviously this is over simplified)
The problem with this is that the process breaks down when a new job interrupts the process. So say you do a copy job, and then another one, but the first one is getting deleted, and the 2nd one is getting processed at the same time, when the first one gets checked for deletion, the files from the new job are still there, and the overwrite code is not able to distinguish this set of files from the one it just deleted, and it then assumes it failed its duty, and displays the "Immediate Disk overwrite failed" message.
In reality it did not fail, so the message is as far as I have been able to discern is totally false. But for the sake of security you are told to perform the overwrite manually.
The firmware I linked is the absolute latest , it is only a few days old, so I can't say whether the issue will 100% have been rectified, I can state it has definitely gotten better in newer releases.
If you are not worried about people stealing the harddrive/data you can disable the option entirely, or make it a daily/weekly/monthly thing instead.
In CWIS go to Properties > Security > Image Overwrite Security > Immediate Job Overwrite and set it to Disabled
Then select Disk Overwrite and set it to scheduled and set it to a time when there is little chance it will be used. Like 6 PM if you close at 5 PM for instance. Can be daily, weekly or monthly.
