Interface lag in Ubuntu 9.10

[huw]

Avi, it's been a while so I hope you see this!  I finally got around to
following your advice.

On Tue, 2009-11-17 at 11:50 +0000, Avi Greenbury wrote:
> Does the restricted drivers manager offer any other versions of the
> driver? 
> Also, search the ubuntu bug tracker[0] for your chipset and/or driver
> version.

I changed down to the oldest nVidia driver offered by the restricted
drivers manager, i.e. 96, and restarted.  No dice.  I haven't searched
the bug tracker yet though.

> > > Are X or GDM writing anything interesting to their logs?

All I can see is this:

(WW) NVIDIA(0): 
(WW) NVIDIA(0): No modes were requested; the default mode
"nvidia-auto-select"
(WW) NVIDIA(0):     will be used as the requested mode.
(WW) NVIDIA(0): 

I'm fairly sure I always used to see that.

I'm no expert but it doesn't really "feel" like a graphics thing.  When
I click an icon - like send/receive in Evolution for example, or
clicking a launcher in the top panel - it registers straight away.  The
icon/button goes into its "pressed" state.  But there it stays for a
second or so, before coming out of the pressed state and my command
being carried out.  There's also usually a lag of a couple of seconds
before the corresponding sound effect is played.  It's as if every now
and again, when I ask Gnome to do something, it has to think about it
for a sec.  It doesn't appear to make any difference whether I'm
launching an app or clicking something within an app.  Quite puzzling!

Any other thoughts would be most welcome.

Huw