mtd partition1 corruption during writes to JFFS2 on partition2.

[Vipin Malik]

I've got multiple mtd partitions on one NOR flash device (CFI/AMD).

I've got JFFS2 fs mounted on the last partition. The other partitions hold 
compressed firmware, that I intent upgrade while JFFS2 is being written to.

However, I find that if I write to the mtd device(s) (erase, followed by 
dd) and then reboot, the firmware is corrupt.
If I stop writes to the JFFS2 partition before upgrading the firmware on 
the mtd partitions, everything is ok every time.

Is this a known "feature"?
Ideas?

TIA

Vipin