RB150 hangs

Hello

I have a few of these and have the same problem on many of them.

After hours or weeks all LED’s will go out except teh blue one on the side, all ether liight will also go out and the router is no more untill reboot.

It seems to happen more often when plugged into a hp procurve but this last oen was just plugged into another rb.

Is the 450 more reliable?

Has anyone else seen this?
I only use them as switchs becuase I thought they would be more reliable (and I can script power outages etc)