Beagleboard not getting Hardware address

I have a very weird issue with the Beagleboard. I have two
Beagleboards, one Rev. B6 & C4. Sometimes in both the boards it does
not get any hardware (MAC) address when i check it by "ifconfig"
command. I do get IP address though. The problem due to this is that i
am not able to access internet whenever i dont get any Hardware
The weird thing is that i do not change any settings, then also
sometimes it gets the address and sometimes not!? Does anyone have any
idea about this?

Thats weird indeed, cos the drivers usually take care of the mac address during initialization itself and do not load if they do not have a valid address (atleast thats how we wrote the drivers a while ago). You can try the following steps in addition to raising a bug (once you are sure you can reproduce the bug, or have a sure-shot way of reproducing it).

1. Try to 'down' the interface and 'up' it again
2. Run: ifconfig eth0 hw ether xx:xx:xx:xx:xx:xx (as root and see if you are able to set it).
3. See if similar thing happens with desktop (plug the ethernet dongle into your desktop)..

Have fun,