it now seems that it is actually when i double tap in the top right corner of the mousepad. any ideas??

hi im' running opera 12.16 on linux mint. When using my mousepad vertical scroll line that runs along the edge, the browser will open up a new tab every now and then, seems like it is the last search that i did, or something else that ive' searched. i turned off mouse gestures and deleted all shortcuts that i found in the mouse section but it continues to do it. this usually happens when im' scrolling up/down very quickly when reading something.