Question

$('input').keypress(function(e){
        var k = e.keyCode ? e.keyCode : e.which;                                     
        console.log(k);     
});
<input type="text" name=""  autocomplete="off"/>

In FF for ‘.’ (point) and for ‘delete’ it is the same code 46.
AND for ‘right’ (right arrow) and for ‘ it is the same code 39.
just to be ‘safe’ Chrome and IE7 don’t fire nothing for keys like arrows, delete, insert, backspace etc

Answer 1

Not really a bug per-say, just one of the many browser differences. If you look on your number-pad, they are the same key, their mapping points to that key.