On one of my dashboards I can move between tabs by 'holding down mouse button (left or right) then sliding left or right before releasing the button. I have tried it in three different browsers with the same result. It does not matter which tab I do it on. It also happens when I use a horizontal slides. If I do a left slide it cycles clockwise and a right slide will cycle anti-clockwise through the tabs.
I have other dashboards where this does not happen.
Has anyone experienced this baffling effect and knows what is behind it. I'm stumped.