Cpu bottleneck?

Hello, I just recently upgraded from a 9600XT AGP to Sapphire HD2600XT GDDR3 AGP version, my system is Athlon XP 3000+ 1GB ddr3 ram
This upgrade brought almost no improvement in TF2(only game tested), I can however play on higher settings, but the frame rates are the same on any settings, all low, dx8.0, or all high on dx 9.0.15-40 fps. however my 3dmark03 score went from 3800 to 11000.

I just ordered more parts because i think the cpu is bottlenecking the GPU's potential. the reason i think this is because it gets the same frame rates no matter what settings its on, maybe a 10% increase from the 9600XT
I went with Athlon 64 X2 4000+ and 2gb ddr2 800 ram
Was this the right move? is this a cpu issue ?

bro i dont think u can run ddr3 and AGP. (did u mean DDR?)
and i take it that u got a new mobo to right? the HD2600 is not the best card. u might be getting a bottleneck.

The graphics card has DDR3 memory.

Yeah the CPU probably is the issue. TF2 is a demanding game for being based on the source engine. The Athlon Xp's had a very good run, I only just replaced mine a year ago, but if your are a gamer than it just won't keep up. Also AGP is dead. But I had a GDDR3 based AGP video card in my last computer and I'm sure the bus was handling all that data just fine. The CPU is most likely the bottleneck.