Disable middle click

This seems to be controlled by some gnome settings that can be manipulated with the "gsettings" command.

$ gsettings list-keys org.mate.Marco.general
will list they keys, among which there is action-middle-click-titlebar.

Although I am not using mate and marco, when I try
$gsettings get org.mate.Marco.general action-middle-click-titlebar it returns 'lower'.

Perhaps you could try setting it to something else or empty, e.g.

$ gsettings set org.mate.Marco.general action-middle-click-titlebar ''

Perhaps it is necessary to restart marco to see the effect (logout probably does that). If this doesn't change things as you want, you could try putting something like 'none' insteady. I noticed 'menu' exists, you could try that.

Does anyone know a documentation that lists the keys used by marco and their possible values? This is one thing I find irritating with MATE and marco, I cannot find any documentation of these settings.

I am now using fvwm, although it is not that easy to configure, at least it is easy to find a complete documentation on how to do it.

Thanks. I tried this workaround-

xinput list
I figured out that the trackpoint a device 10

xinput get-button-map 10

and by trial and error found middleclick is the third column.

Then:

xinput set-button-map 10 1 2 0 4 5 6 7