Are you sure there is no MAC address filtering within the router? Not using mac address fltering. Maybe http://elinux.org/R-Pi_Troubleshooting#Networking_no_longer_works_when_changing_SD_card_between_two_Raspberry_Pis is relevant. Thought of that so just to make sure tried a clean new install and s...

I am am unable to get a dhcp lease with ip with the 512 mb version, yet with the 256 mb version using the same SD card with the same OS, it works fine. It appears as though it is specific to the 512 mb version, and not software related, as I have experienced the exact same results with 5 different O...