Table cells not resizing for Responsive HTML5 output

The attached images show the different results I get in the Responsive HTML5 output when (all other things remaining the same) I set the cellbody size to 9 pts via either the FM paragraph designer (correct looking image on the left), or via editing the cellbody font size to 9 pts (down from 12 pts) when in the Publish Settings window and selecting Edit Style to decrease the cellbody font size.
. Ideally I'd like to decrease the assigned font size in the HTML output (compared to the PDF output), but this issue in the cells is causing me grief. The table has the default cell padding values assigned in the Table Designer (6pt, 6pt, 4pt, 6pt) and I can't decrease these as it messes up the look of the tables in the PDF output. Can anyone shed any light on why this is happening and whether there's a fix or a work around? Thanks!
