Note the code at the bottom of the base:
* {font-family:Verdana, Arial, Helvetica, sans-serif;margin:0;padding:0;}body {{% if theme.background_image != blank %} background-image: url({{ theme.background_image.url }}); background-repeat: repeat; background-attachment: fixed;{% endif %}background-color:#FFFFFF;color:#00000;font-family:Verdana, Arial, Helvetica, sans-serif;font-size:11px;font-weight:normal;margin:0;text-align:center;}ul,ol {margin-bottom:1em;}li {list-style:none;}h2 {font-size:13px;font-weight:normal;margin-bottom:1em;text-transform:uppercase;}p {color:#00000;font-size:11px;line-height:15px;margin-bottom:1em;}a {outline:none;text-decoration:none;}a img {border:none;}a:hover,a:active,#products .product-a:hover h3,#products .product-a:hover p {color:#91a3b0;}#products,#products .product-pic,#product-images .images-nav {background-color:transparent;}input,textarea {color:#00000;font-family:Verdana, Arial, Helvetica, sans-serif;font-size:11px;font-weight:normal;}hr {background:#ccc;border:none;color:#ccc;height:1px;margin-bottom:10px;}#wrap {margin:0 auto;text-align:center;width:970px;}#header.image h1 span,#minicart .minicart-view span,#minicart .minicart-checkout span,#search-submit span,#badge span,div#error h2,div#error p,.pagination span.disabled,#product-images .images-prev span,#product-images .images-next span,#inventory .bar span em,#update-btn-head,#head-options span,#cart-body .item-options span {display:none;}body,p,input,textarea,#product-details .price,#faq-content .faq-list dt,#contact-form label,#cart-footer .cart-total #cart-shipping-tax p,a:link,a:visited {color:#00000;}#product-1,#product-4,#product-7,#product-10,#product-13,#product-16,#product-19,#product-22,#product-25,#product-28,#product-31,#product-34,#product-37,#product-40,#product-43,#product-46,#product-49,#product-52,#product-55,#product-58,#product-61,#product-64,#product-67,#product-70,#product-73,#product-76,#product-79,#product-82,#product-85,#product-88,#product-91,#product-94,#product-97,#product-100,#product-2,#product-5,#product-8,#product-11,#product-14,#product-17,#product-20,#product-23,#product-26,#product-29,#product-32,#product-35,#product-38,#product-41,#product-44,#product-47,#product-50,#product-53,#product-56,#product-59,#product-62,#product-65,#product-68,#product-71,#product-74,#product-77,#product-80,#product-83,#product-86,#product-89,#product-92,#product-95,#product-98,#product-3,#product-6,#product-9,#product-12,#product-15,#product-18,#product-21,#product-24,#product-27,#product-30,#product-33,#product-36,#product-39,#product-42,#product-45,#product-48,#product-51,#product-54,#product-57,#product-60,#product-63,#product-66,#product-69,#product-72,#product-75,#product-78,#product-81,#product-84,#product-87,#product-90,#product-93,#product-96,#product-99 {margin:0;padding:0;}
^ Does it have something to do with how the product numbers are ordered? This style sheet used to only display the products 3 across the page before I started messing with it, and now I've gotten it to do 5 across.