Logitech MX518 gaming mouse button assignments

Archived from groups: alt.games.half-life.counterstrike (More info?)

Everytime I go into counterstrike,
the mouse button that I have set
for accesing my main weapon keeps resetting
from mouse button 4 to mouse button 5.
It sometimes resets itself from round to round.

This is really annoying. I buy my gun, try to access
it and find, over and over, that I have to find a safe corner
where I can go to the options and re-assign to the right button.

Has anyone else had a problem with this model?
Suggestions?

I have a Logitech MX700 and have used the windows mouse configuration tool to assign the extra buttons keypresses, e.g. button 4 I have assigned 'l' for last used weapon, button 5 I have assigned 'w' for walk, button 6 I have assigned 'd' for drop, button 7 I have assigned 'g' for spray logo and button 8 I have assigned 'b' for buy.

This means that the buttons can no longer do anything useful in windows but I have never used them outside of gaming anyway.