Upgrading system......is it required?

Hi,
I am subhadeep from india....
I am a part time gamer , playing games ~10 hrs in a week.....
In my view I don't need a power house....just want to run games in mid or high-med settings in ~30 FPS.
My system config is
AMD Athlon 64 3500+ venice
MSI K8N Neo4 platinum
2 X 512 MB DDR RAM
160GB HDD sata
XFX 6600Gt 256 MB PCI Express X16
Antec 450w smert pawer 2.0
LG 17" TFT....1024*1080....

PCMARK04 4354

Till now I am not having any problem with new release.......
I am getting decent frame rate in med high settings in various titles.....like COD 2, FEAR, Tomb Raider: Legend, Splinter cell : Chaos Theory etc.....
Now with a new title NFS :Carbon......i am getting a lot of problem. cant get 30 FPS without midlow settings.....

Is it the time to upgrade my system? or that is the bug in game only....
please remember .....I am not a serious gamer......

a slight upgrade with your vid card should help. apart from that there is nothing really needs changing. look up the november buynig guide for an idea of what to get.

if you have the cash, you should upgrade till you get the desired performacne. in your case it is the vid card that need replacing.

1gb should be fine, your current psu should support the 7600gt, but you'll need to get a new one if you get a 8800gtx/gts.