In NS7.1/ColorPicker.js make the following changes:

Add this at the top:
var heldDown = 0;

// Then down below change these
function pnlVertical_Top_MouseMove(e)
{
// if(e.which != 1) return; // Commented out
if(heldDown != 1) return; // Added
SetVerticalPosition(e, e.pageY - 5);
e.cancelBubble = true;
}
function pnlVertical_Top_MouseDown(e)
{
heldDown = 1; // Added
SetVerticalPosition(e, e.pageY - 5);
e.cancelBubble = true;
}
function pnlVertical_Top_MouseUp(e)
{
heldDown = 0; // Added
SetVerticalPosition(e, e.pageY - 5);
e.cancelBubble = true;
}

Thanks,
Brian

The last few releases of Firefox have caused some weirdness in it, though. When you move your mouse over the vertical HSB slider the value changes without having to click.

Any chance of an update?

Thanks,
Brian