Just installed 13.1 on my laptop (Thinkpad X200s) which was running 12.2 for ages.
All seems well except that the use of button1+button3 as button2 is not working. This is a serious problem as the middle button is not really working. It was OK on 12.2
I run X with fvwm as window manager; no gnome or kde. Where should this be configured?