Ubuntu video slow

[George]

I installed Ubuntu two days ago and I'm very satisfied. I hadn't
worked with linux before so I'm learning my way around.

I've managed to install mostly everything I need to keep me from using
windows. I've come across some difficulties with video though.

Ubuntu did detect and install the nvidia driver but everything I do
with gnome seems very slow, opening windows, redrawing them, things
like that. I installed zsnes and snes9x to test the video
acceleration, both were running slow and couldn't get stable
framerate. Compared to windows xp.

Also, ubuntu won't let me set a resolution over 1024*768. That's the
resolution I was using in windows but in gnome everything looks much
bigger so I have trouble working like this on my desktop.