Possible question of 'port' (as in USB or something)
I have Slackware and RedHat Linux on my laptop, and I have a touchpad mouse (on the laptop), and a USB Optical mouse (which I think has a PS/2 adapter for other computers, right and left buttons, a wheel, and two buttons on the left side), from Microsoft. The mouse I have is called an IntelliMouse, and it can plug into the USB port.
Maybe the mouse you are using is able to work with IntelliMouse. It may not be, but if it is, then try that. IntelliMouse I think can also be seen on some computers as PS/2 (using the adapter), or USB (not using the adapter).
The way I set my computer up:
I installed Slackware Linux, and I had set the mouse to be, I think, a generic PS/2 mouse (the Synaptics TouchPad mouse on my laptop). I then set up the test kernel, and made the changes I needed to make. Then I plugged in the USB mouse without the PS/2 adapter.
It seems that on my computer, the IntelliMouse (which Slackware sees as a 5 button mouse), is able to work just fine. So, I would recommend with extreme caution, to try the IntelliMouse setting. It could be, although I am not sure, that Slackware may be able to see the mouse as Microsoft IntelliMouse or compatible, so I would very cautiously recommend you look at that and, if you so elect, change the mouse type to that. There is the possibility that it is similar.