I'm running version 3.7.1 from the Gentoo distribution, 64-bit.
Assuming the default keyboard layout, enable free camera mode by pressing f.
Press w/a/s/d to rotate the camera. Instead of the rotation stopping once the key is no longer pressed, it continues rotating forever (if left/right; if up/down, until the camera hits top/bottom) in the same direction until free camera is disabled by pressing space. If f is pressed again, the camera will rotate by itself in the same direction again.
There is a possibly related bug with the setmarker command, enabled by the x key. Once x is pressed, all clicks, not just the first one following the keypress, produce a temporary marker on the map, which rapidly gets annoying.