Quantity selector on products page

[zsoundz]

The quantity selector increases by 2 (next to add to cart), eg click + and the value goes from 1 to 3 to 5 etc,

I also added the lines below to stockable.php line 403 to address the bug for custom plugin for managing stockable product variants

if (quantity == undefined){
quantity = 1;
} /* this is the new bit */

Is there a solution I'm unaware ?