Need 6.10.2 firmware

I have a ReadyNas 316, which I updated to OS 6.10.3 a month or so ago.  My backup USB drives are no longer reliably identifed by the device, which I think is due to the OS upgrade.  I've tried multiple drives, all have the same problem, and all work well on my Windows PC.

Anyone know where I can get a copy of the previous firmware, 6.10.2, or alternatively if there is beta firmware which addresses this problem?

Thanks!