hi!
Can you verify if the remote device is having any problems recognizing 802.3 frames? could it be possible that that remote device is getting the 802.3 frames but not responding atall?
The second thing is that since the ping from remote device works, it means that your ICMP replies are going out of your subnet to the remote device. Else ping would have been unsuccessful from that end too. So I think the network would not be a problem here.
Regards,
Niranjan