Really?!? Weird.
The configurations are stored in both RAM and ROM, but the ROM is only read and validated at startup. You said the firmware is up to date, did you get it that way, or have you updated them? The firmware and config are stored in the same part.
We have never heard of this that I am aware of. Since you have more than one failing module, that tends to point to something else...like base power supply. However...the reset chip on the module should kill them if the power drops to about 4.5v, which is inside the spec for the flash parts. I have no clue.
I'd like to swap modules with you and see if we can duplicate the problem here.