I have two MT 532's with newly upgraded 5.12 code. Each has an ethernet connection to a wireless radio and seem to pass traffic ok until we transfer a large file. The file starts out transferring and gets about half way or so and then the connection drops. I have noticed the "R" next to the ethernet3 interface of the 532 at bottom left in my drawing (see attached) disappears and then re-appears when this happens. So I moved the ip off of eth3 to eth2 and start the transfer all over again. Same thing happens. The Health screen is blank and just says apply and close and there is no other data within the window. We have disabled auto-negotiate and hardset the connection on the MT interface to be 100 full. Any ideas?

Could it be a bad routerboard?
Is there later firmware for the 532?
Does the 532 not have the ability to transfer such a large file (CPU?)