[RUNGSI]

Well i had the same problem.
I upgraded to a new card and my Frame rate dropped..
I did a lot of investigation. (not joking, A LOT!)

I had a AMD Tbird 1 gig with 512mb pc133
What I found was with Nvidia making these extreme cards, they dont tell you that you need a bad ass comp to use it. The frame rates they promiss can be done. Most frame rate tests are done on dual prossesor machines or overclocked.
I was pretty pissed off myself. Spent 400 bucks for a card and my frame rate dropped.
What you are getting is normal and with the setup you have now. there is nothing you can do about it.
Basiclly your Processor and memory is bottle necking it.
Your going to have to get a new machine in order to take full advantage of the GeForce4

I went on to build a new machine
AMD 1.733mhz
1 gig pc3200 extreme ddr
asus 333 motherboard (piece of crap) getting the new nvidia motherboard soon enough.
40gig ATA 133 hard drive
431w powersupply
Custom case, with a lot of fans for cooling

Now.. Its extremly hard for my frame rate to get lower then 60
I would go with AMD
Stay away from Intel

I have built a lot of machines and AMD has always out performed Intel.
Intel is good for 1 thing. Less need of service (cleaning)
When people come to me with "I want the ultimate gaming machine" I sell AMD
When people come to me with "I want a up to date office machine" then they get Intel.

I get these issues all the time from people.. Its a shame they never came to me first.
I wouldnt point you in the wrong direction. I have been there. Lived it.. Pissed off..