Yah, worked for me as well although I'll try setting to 1 instead of 0 and see if it makes things smoother for me.Its good to hear this trick is working for others as well. I have also tried the setting as 1 and for me seems a bit smoother for scrolling in Firefox so worth experimenting. It can only be 0-4 but I'm guessing higher numbers may make it worse.
Its worth noting though that if this does work for you and you run the Nvidia settings program the entry will be removed as the .nvidia-settings-rc file is over written on quitting the program, you will have to remember to re-insert the line manually or the old problem will come back.
I'm not sure if this only effects earlier Nvidia chips. I have a 460se which is now the lowest the new drivers cover and I'm wondering if anyone is experiencing the problem with the newer 800 or 900 series chips, I'm thinking of upgrading some time in the future.
Oh, and I installed the brand new "Graphic Drivers" PPA so I could upgrade to the latest 355 driver and just to make sure, I checked the driver compatibility list at the Nvidia drivers site and this driver covers all the 400 series from 400 on up. This is good because I have the GT 430 Media card installed. Looks like I'll have to look into a newer video card in the next few months.