How did you install this plugin with regards to your original template? If you simply overwrote the files, then you didn't do your cart justice. No plugin that has template files incorporates the new code with the existing code just by overwriting. Need to merge previous with current and understand that the software provided in a plugin is some version of a vanilla copy of the ZC file with changes made to support the plugin.
That, and again I would say that there is a html validation issue that existed before adding this plugin or in adding it one was created.
Bookmarks