Hardware

I have my WG X500 and when I try to add the other interfaces they add fine, but when i go to bridge them, the OS locks up.  i end up power cycling it then i can get to the interface page to bridge them but it slow way down.  any ideas?  Oh,  this happens on both of my X500's  i tried using the 1.8 image as well and the same things happens.   could it be that im running out of ram, its only 256mb   thanks