So, I ssh to the router ... and there it goes for about 5 lines, then it freezes. If I put the serial cable on the console (doesn't have to a terminal connected to the cable but it is plugged in) it starts to send lines again ... seems like a bug to me ... if it isn't, can some prove that they can reproduce it so we can submit

Here is the firewall rule I put at the to of the output chain:
/ip firewall filter add chain=output action=log protocol=icmp
then:
/system logging add topics=firewall action=echo
Then it will freeze up if you set a client to ping through the router.