What is the Shipped State of Serial Flash on RCM3315?

My client has a product built on RCM3315 that uses the FAT filesystem in the serial Flash. This product has shipped hundreds of RCM3315 in the past 4 years. One of the earliest code features was detecting a fresh RCM board, with no FAT partition, and formatting that partition.

Recently, a small percentage of RCM3315 boards are failing that operation. I have had to add code to format the device and repeat the partition format if the initial partition format fails.

This leads to the question, whet is the intended shipped state of the serial Flash? I think the ones that fail the initial partition format are just blank. So what is on the rest of the serial flashes, and why is there a difference?