If it were an issue with the ethernet port wouldn't that prohibit me from connecting to the blade via web browser to configure it?
I would think so. You have several Blades running so you have the setup down, you've tried different cables and ports so I think that would rule out anything on the net side. I would think it's related to this particular Blade, defective ethernet components?
This lists color/blinking to speed and activity.
http://pic.dhe.ibm.com/infocenter/ts7700/serv/index.jsp?topic=%2Fcom.ibm.storage.ts7740.service20.doc%2Fts7740_maint_ethernet_led.htm