DOCBOOK-APPS: Table frame, colsep attributes ignored in HTML

["Bradford, Denis" <denisb at rational dot com>]

We want to do some tables like this:

----------------------------------
Col Head 1  Col Head 1
----------------------------------
Cell 1          Cell 2
----------------------------------
Cell 1          Cell 2
----------------------------------

The following code renders fine in old DSSSL print FOSI. But HTML generation
using chunk.xsl ignores table frame and colsep attributes below. Tested with
db.xsl V 1.48 and 1.50:

<table frame="topbot" colsep="0">
<title>Titled Table Without Column Separators</title>
<tgroup cols="2"><colspec colname="col1"/><colspec colname="col2"/>
<thead>
  <row>
    <entry colname="col1">Column heading 1</entry>
    <entry colname="col2">Column heading 2</entry>
  </row>
</thead>
<tbody>
  <row>
    <entry colname="col1">Row1 Cell 1 text</entry>
    <entry colname="col2">Row1 Cell 2 text</entry>
  </row>
  <row>
    <entry colname="col1">Row2 Cell 1 text</entry>
    <entry colname="col2">Row2 Cell 2 text</entry>
  </row>
</tbody></tgroup></table>

The HTML table simply has <TABLE BORDER="1">, as if we had set frame=all. I
tried turning on table.borders.with.css, but then I lose all table borders,
including those with frame=all. Is there some parameter(s) I'm missing? 

Thanks,
Denis