I have a serious router issue?

I just bought a new Netgear WGR614 router I have an old D-LINK DI-514 router too. My old D-LINK works very good the only thing is its a B router and WPA PSK doesnt work properly. So I am trying to upgrade to this G Router netgear. I set it up alright with the disc it came. It was a success, But once I connect to to the internet again it goes very slow. I mean sometimes it will load a page after 30 seconds sometimes it will not load at all. I plug my dlink back on and it works like it should very fast. I have 4 mbps comcast cable internet. So I am wondering how do I resolve this? firmware on both ends are up to date. I have a connection to the internet through the router but it is either to slow and times out or it doesnt load a page at all. Maybe I have to configure something either with the NIC or the router, I dont know what to do.