There was a temporary glitch with the activation server last night, it is back up and running now though, try to activate again, it should go through.
If you still have a problem, go to the System Preferences -> Network panel. Select the active connect and click the Advanced button. On the Ethernet tab, note the Ethernet ID
Send the Ethernet ID and the eCart serial number in a private message, i can use those to generate a license for you.