I have that same router in a mixed PC, Mac, PS2 network. No problems here.
You realize that besides setting up the router, the client machines must be changed as well. For example: if you formerly had your Mac straight connected to your DSL, you probably had it set to use PPPoE in the network settings (and you had to put in a username, password etc. to connect to your DSL account). Once you have a router, the router itself is the connection to your DSL account and all machines hooked to it need to be set to passively receive the signal it provides. In other words, they should be set to be DHCP clients to the router.
Check these two things:
In the router config (192.168.0.1) check the "Router Status" item on the left. If it is properly connected to the internet, you will see an IP address listed under Internet Port -> IP Address. There is also a "Connection status" button at the bottom you can push to see if your router is connected. If your router is showing that it is connected, then your problem probably lies in the setup of your machines. If the router is not connected, then the problem is in your router config or in the DSL modem.
In your Mac's Network Preferences, look at the location you are using --> Built-in Ethernet. On the PPPoE tab, make sure that "Connect using PPPoE" is UNCHECKED ... otherwise your computer is still trying to manually connect to the internet instead of just receiving the downstream signal from the router. Once you've unchecked that, go back to the TCP/IP tab and choose "Using DHCP" from the "Configure IPv4" dropdown. Hit 'renew DHCP lease" and then the 'Apply Now" button at the bottom. Usernames, passwords, and connection info has all been moved to the router now ... you need to take it out of the individual computers as they no longer need it and , in fact, will no longer work if you try to connect this way. The computers are now DCHP clients of the router and need not maintain an internet connection of their own.