Changing "inside" to "outside" in list-style:
will take care of that.

You will then need to refigure left margins. Make configuring easier by altering the style property wording a bit:
Code:
#categories ul a {/*top categories*/
    display: list-item;
    list-style: disc outside url(../images/bullet1.gif);/*change to list-style: none; to remove bullet*/
    background: no-repeat;
    border: none;
    margin: 0 0 0 5.0em;
    padding: 0;
    }
For the individual category rules, make the rule apply only to the marker url:
Code:
#categories li.cat-vouchers a {
    list-style: disc inside url(../images/cat1.gif); 
    padding: 0em 0em;
    }
/*change all individual cat rules as below*/
#categories li.cat-uniforms a {
    list-style-image: url(../images/cat2.gif); 
    }
If you want to improve the vertical alignment of the bullets and text, you will need to move the list styling from the <a> back to the <li>. This will not be difficult; let me know if you need help.