oh. and i forgot to say that.. without the router.. if i connect directly through the modem.. i can connect to the internet. only through the router i can't connect

Does SBC require that you use the PPPoE protocol to connect? If so, check your router's setup/configuration page and make sure that it is set for the correct protocol. Most routers default to using the DHCP protocol, which works for Cable connections, but most DSL providers use PPPoE instead.

Did you reboot your Speedstream after plugging in your router? Often they will only remember one MAC address and need to be rebooted before seeing a new one, drives people crazy.

1 power everything off
2 plug pc into router
3 plug router into Speedstream
4 power up Speedstream, wait 30 seconds
5 power up router, wait 30 seconds
6 power up pc and pop open a web browser

Then you will know if you need to do more troubleshooting.

True- that does happen; do as w1r3sp33d suggested in that respect.