PS2 mouse

I have an older computer (not the one where I am posting this). It has a PS/2 mouse.

When it was running openSuSE 11.3, the mouse behaved just as expected. It’s a microsoft Intellimouse (if I recall), and I often used the mouse wheel as a middle button for pasting text or for opening web pages in a new tab.

Now that I have installed 11.4, I notice that the mouse is behaving differently. It ignores a middle click. It does respond to simulated middle click (left+right buttons at the same time). And it also responds to a double click with the middle button (the wheel).

Is there a way I can configure it to get it back to how it was on 11.3? I didn’t find any settings in KDE that were relevant. And Yast seemed to only have settings when used in text mode (on a virtual console).