Hmm doesnt sound quite right. I have Radeon 7200 which has slower SDR memory and it scores with drivers default settings around 2500 on 3Dmark 2001 SE - which btw is about 300 points more I ever got with overclocked Geforge 2 MX card.
Oh and I only have 800Mhz thunderbird.
Try updating your drivers is my advice. The latest beta from Ati site has been working great for me.