So this appears to be 100% Xorg's fault instead of an engine issue. So what you want is to configure your mouse so those buttons are button6 / button7 When mouse wheels first started appearing, mice never had more than three buttons, so mousewheel up/down defaulted to emitting Button4 and Button5 so apps would have something to listen for
In both cases I am absolutely not pressing MOUSE4 or MOUSE5, but their respective codes are being sent along each time I scroll. Similarly, whenever I use MWHEELUP to hop faster into ledges (I practice KZ), I hear the sound that +use produces (triggers MOUSE4).
Whenever I bunny jump using MWHEELDOWN, my sound stops briefly each time I scroll (MOUSE5 is being triggered). In my Counter Strike 1.6 client configuration file I have the following binds:
