Slow window repaint under 'Etch'

[Peter Hillier-Brook <phb@hbsys.plus.com>]

Hello All,

Can anyone suggest a starting point for me to analyse the very slow 
repaint of windows following an unidentified update of 'Etch'? By very 
slow I mean that dragging a window across the screen results in quite 
impressive staggering of the window, suggestive of high alcohol 
intake:-) Performance in all other respects seems fine.

Relevant factors are: Gnome, ViewSonic LCD screen with ATI X700 graphics 
card running on an AMD Athlon 64 3200+.

Running similar software on 800MHz Pentium III systems - i.e. much 
slower machines - but with a different graphics card and a glass screen 
results in normal performance.

My guess is that something in 'X' has gone amiss, but all upgrades are 
current on all machines, so the only obvious place of difference seems 
to be xorg.conf. Does this make sense?

Thanks for any pointers including, if necessary, RTFM (with a hint as to 
which 'M').

Peter HB