Hello.
You "set your primary DNS to your gateway". Do you mean in the SME setup screens you did not leave the DNS blank (the default) but instead put the gateway's IP?
If yes, then remove this setting and reboot. The SME will automatically querey the root domain servers for IPs outside of your own domain.
You didn't give much detail, so I must guess...
* set the SME to use no DNS server IP, leave the setting blank. Reboot.
* Assuming you have a firewall or router acting as a gateway, use THAT machine's IP address as the gateway the SME needs so it can discover a path out to the Net.
Should work just fine.
??
patrick