Comment 9 for bug 1417209

I'm experiencing the issue too, under Ubuntu 14.10. I'm happy to install something bleeding-edge on the laptop for experimentation; it's not like the laptop is terribly useful without working mouse buttons.

Given that middle-mouse button scrolling is implemented in the trackpoint driver, and the middle mouse button (when it works) will be firing in the synaptics driver, I'm guessing that even when the buttons are fixed, middle-mouse button scrolling will still be broken. Just like the 2014 refresh Lenovo laptops without hardware mouse buttons (see bug 70780).