Harpoon wireless mouse activates right click when landing mouse.

I noticed something odd when playing a game recently. The melee which is assigned to right click would randomly activate. At first I thought it was the game but now I've realized its the mouse doing it when I land the mouse after moving it. It also seems to have started happening after updating the firmware, but that could be a coincidence.

Overall not incredibly impressed with this mouse, it also has a tendency to stutter, especially when plugged into the back USB ports of my PC for some reason.