#87 Button Stuck

[Anonymous]

One of my button appears to be stuck. I've got it assigned to 3 normally and 7 with the Shift+. Clicking the button itself does nothing. Now whenever i push the Shift+ button abd hold, a 7 is typed. Releasing types a 3.
Until recently, pressing the SHift+ would cause 3 to be continuously typed until some other button was pressed. Is my mouse broken?

[Anonymous]