Thanks; that got me in the right direction
I had looked at dpkg but hadn't seen the --force-downgrade option. In point of fact, that didn't work, so I downloaded the apache2-common and mpm-prefork from 2.0.44-6, which worked fine, which then allowed me to install mod-webapp like I wanted. :)
Many fears are born of stupidity and ignorance -
Which you should be feeding with rumour and generalisation.
BOfH, 2002 "Episode" 10