i am having a similar problem, but only in firefox. when i do a search in explorer, it seems to be fine.
www.midweststereo.com is the site. do a search for denon or digidesign, or anything really. those just have enough products to show the difference.
anyway, the products list fine in explorer, but in firefox they tab over a column on each consecutive result, making about 5 products listing before they go back to the left and start the process over again.
any ideas? i've gotten this problem reduced to what you see now. it originally caused the page to expand by about 300% of the monitor width. i can temporarily live with it the way it is, but i do need to find some solution. the first part was solved by fixing some tags in the search template. i then switched from Default Page Template (which i could not actually find in the templates directory) to search_link in the link template override box, and that helped greatly. it solved the problem completely in explorer, but you see the result still left in firefox.