Your PC133 ram will be causing a little bit of a bottle kneck, especially in the madbunion tests. Try uping the speed of your FSB, that may make up a little for your memory.
After that try oc'ing you 4200, cranking up the core speed will improve fill rates, aniso, and stuff. Cranking up your memory speed will incease FSAA and general rendering speed.
Folding for Beyond3D
"A lie gets halfway around the world before the truth has a chance to get its pants on."
Sir Winston Churchill
"Halflife2 got halfway around the world before Gabe had a chance to get his pants on."