The solution is here, i quote the author:
"You have to Add the middle mouse button (MMB) twice and translate
both events to the left mouse button, like this:
Click Add.
Deselect the "No mouse" (to be able to record mouse events).
Click the MMB on your mouse once.
Select the "No mouse" again (to be able to use the mouse).
Select the first MMB event in the list (not the upstroke).
Click "Use code".
Click "Translate" and record the left mouse button (LMB) the same way.
Now you should have an MMB event that translates into LMB.
Click "Duplicate" to copy this event.
Try it! :)
You might also need to create a third copy of the MMB code and
translate it into LMB upstroke. Some programs might get stuck
otherwise. Just experiment a little."
And Yes, you must create a third copy od the MMB code and translate it into LMB upstroke to work perfectly!