Video problems with Unity on older laptop

[MR ZenWiz]

This is a genuine technical question, so hopefully it won't set off
another firestorm controversy liek my last post (sorry about that -
really).

My "new" laptop is an HP NW9440 (Core2Duo CPU, 2GB RAM, 17"screen)
that has an nvidia Quadro FX 1500M video card in it.  It came with
Win7 and I put Natty on it as a dual boot option (so as not to destroy
the Win7 altogether).

Under Natty, it has video problems.  The screen frequently shows bit
splatter trash, usually whenever something gets painted on the screen,
like a terminal window or clicking on an icon - something gets
distorted.

(Bit splatter trash means that there are horizontal streaks of
multicolored pixels that do not belong to whatever part of the screen
where they appear.  Sometimes it's just a few, sometimes it's like
static all over the place.)

I figured this was probably due to the default video driver because,
among other things, Unity would not come up, complaining that there
was no 3D support.

So I pulled down the 270.41.06 nvidia driver with synaptic, and that
improved things a bit, but not enough.  Unity came up this time (and
you already know about that), the 3D support is there, but it still
has a fair amount of screen bit splatter.

I even went to nvidia and pulled down their latest driver, 270.41.19,
which is what they recommend for the 1500M card.  Still get video
junk, though less of it.

Worse, when I tried to play a DVD, I get anything from horizontal
static, a few lines here and there but throughout the video (a George
Carlin DVD), or really distorted, unwatchable blotchy video with jumpy
audio, too (Avatar).  Even the .avi versions I've ripped from these
and other DVDs are messed up.  This happens in VLC and mplayer.  Totem
is missing codecs (as usual - I hate totem), and xine refuses to play
the DVD also (same problem, but I rather like xine).

If I boot Win7 and watch them with either VLC or WMP, they work fine -
crystal clear, no problems at all.  The Windows driver is version
7.15.11.7967, which doesn't map to the Linux revision (of course
not!), and it's dated 3/6/2009.

I'm tempted to install Maverick to see if that makes any difference
(though I'm not entirely sure how it would), but I was wondering if
anyone had hit this already and resolved it.

I found one article using Google that indicates it may be a bad video
card courtesy of HP, but that wouldn't explain why it works so nicely
in Windows.

Input welcome.  Thanks.