Well first, "glowing blue" just means it has a gigabit connection rate, which unless your ISP is google, you don't need. No point of having a 1000Mb connection rate if your speed is only 30Mb or the like. From the sound of it, the firmware downloaded by your ISP may even be forcing a 100Mbps.
Second, if its happening with a NIC, then you have isolated it as a non router issue. I would contact Motorola if you want to troubleshoot it, but really its a non problem. Think you may be a little too focused on the blue lights. Heh
Last, if you want to test the WAN port on the router, just connect the Gigabit NIC to the DIR-655 WAN port, make sure both are on 1000Mbps and reboot the modem. Even though it won't give you a usable connection, it should still form a physical 1000Mbps connection.