Inconsistent Heading underline in Accordion with Smoothness with FireFox

Inconsistent Heading underline in Accordion with Smoothness with FireFox


In the accordion using the smoothness theme, the default div, and
every other div (i.e., odd numbered sections), have a border
separating them from the content. The other divs (i.e., even numbered
sections) do not have a border.
This problem only occurs in FireFox.