HTML output informaltable / no space-after?

We have a DocBook file with lots of informaltables, one after the other.
When I transform it to HTML, there is no space after theses
informaltables. This makes them look as if it was just a single, very
long table.

I have checked the <xsl:attribute-set name="table.properties">, but the
entries are okay.
Where do I have to adjust the settings? Or do I have to adjust the CSS
file?

Regards,
Martin 
 
*******************************************
Harman Becker Automotive Systems GmbH
Geschaeftsfuehrung:  Dr. Peter Geiselhart  -  Michael Mauser  -  Edwin Summers  -  Regis Baudot
Sitz der Gesellschaft: Karlsbad - Registergericht: Mannheim HRB 361395
 
*******************************************
Diese E-Mail enthaelt vertrauliche und/oder rechtlich geschuetzte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtuemlich erhalten haben, informieren Sie bitte sofort den Absender und loeschen Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet.
This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorized copying, disclosure or distribution of the contents in this e-mail is strictly forbidden.
*******************************************