Maybe you can try Apache2::PerlSections->store($filename); in a seperate perl section?

Hmmm... Provided I also add "$Apache2::PerlSections::Save = 1;" in the first section, I get pretty much what I had expected:

$VirtualHost{'*:80'} = [
                         {
                           'ServerName' => 'vsite1.XXX.XX',
                           'SuexecUserGroup' => 'XXXXXXXX XXXXXXXX',
                           'ServerAdmin' => 'XXXXXXXX@XXX.XX',
                           'DocumentRoot' => '/home/XXXXXXXX/public_ht
+ml'
                         },
                         {
                           'ServerName' => 'vsite2.XXX.XX',
                           'SuexecUserGroup' => 'XXXXXXXX XXXXXXXX',
                           'ServerAdmin' => 'XXXXXXXX@XXX.XX',
                           'DocumentRoot' => '/home/XXXXXXXX/public_ht
+ml'
                         },
                         {
                           'ServerName' => 'vsite2.XXX.XX',
                           'SuexecUserGroup' => 'XXXXXXXX XXXXXXXX',
                           'ServerAdmin' => 'XXXXXXXX@XXX.XX',
                           'DocumentRoot' => '/home/XXXXXXXX/public_ht
+ml'
                         }
                       ];
1;
__END__
[download]

It's as if it's all there except there's a tiny piece of the puzzle missing. A module or library which needs to be loaded, or perhaps some magic incantation that I overlooked? The documentation points out that any misspelled keyword will be silently ignored, that's not very reassuring...