This is a big problem for me too, because I would like every page of my site to validate and still I would like to have "add to cart" button and "quantity" field on my product page. If i remove them everything validates okay.
Also I noticed a bug in the uc_catalog.module - on line 1145 we have
"$product_table .= '</td>';"but it should be after the else closure, just move it two lines below and place it on line 1147.
Joined: 03/16/2008