Not a real bug I guess but something very surprising at first when used to Live since a while :
When I click on 'Bank', 'Sub-Bank' or 'Program', it acts immediately and select a number without having the time to go through the number list.
I've been used to click and look at the number list before selecting the right one for my needs.
I'm still able to do it but I have to click perfectly on the little arrow. This can be annoying during live performances or situations out of the studio where I'm not near my screen or when I have to use this function quite quickly.
PS : just sent a bug reporting snapshot to Ableton. This text is what I sent them.