Long day - Need help

Last Friday I attemted to replace my nat firewall with RB450. Everything went fine for about 2 hours then I installed Dude 3.0rc1 and did a discovery on the router. It quit! Looking at it the yellow light was on but both the internal and external ethernet interfaces were dead. No link light or traffic light. Power cycle fixed it. After another few hours of running I ran a discovery on it from my home network (on the public interface) and it did the same thing. I then replaced it with a duplicate RB450 but with the backed up configuration. I tried to crash this one with a Dude discovery and could not but I also could not crash the first one. After another 2 hours or so same thing. The logs show nothing and I have not hooked up a serial terminal to it to see if it is still alive or not. This is VERY frustrating and I would hope that even a miss configuration would not cause lock up like this. I need some recommendations to try (hopefully offline). I have caused my users more downtime than my past 10 years combined! Thanks in advance.

Pete

Some stats on the network:
10 MB fiber line on the public network
/28 network (all IP’s) on the external interface gateway is a cisco router with one of the IP’s
About 150 devices on the private network with about 50 using the MT for traffic.

Some things to try.
Upgrade to the latest RouterOS. Currently 3.13 http://www.mikrotik.com/download.html
Upgrade the firmware. Currently 2.16

/system routerboard upgrade

Try a port other than ether1 for your internet uplink.

Hope it helps.
-Louis

Update: turns out these are RB150 runing v2.946.