Finally I succeeded again, after almost two weeks, to have the websites back up and running, so apologies. For the fault was on my side. Though some holes are still around, concerning subdomains and php/MySQL. Apparantly also some holes in my understanding of web techniques.
As my former host, Lycos, announced to be quitting the webhosting business end of February 2009, a new one had to be picked. So, from now on, it is Strato who hosts these sites of mine.