You should just be doing this:
var iKey = e.keycode || e.which || 0;
Quirksmode explains your problem well:
The two properties are keyCode and charCode. Put (too) simply, keyCode says something about the actual keyboard key the user pressed, while charCode gives the ASCII value of the resulting character. These bits of information need not be the same; for instance, a lower case 'a' and an upper case 'A' have the same keyCode, because the user presses the same key, but a different charCode because the resulting character is different.