Thanks for the feedback so far. I tried to simulate the problem with the following piece of code:

#!/usr/bin/perl -w
print "Content-Type: text/html\n\n";

my $value = "ciaoslave";
my $allowed = '[\w\d\s\-]{1,15}';
my $escape  = "yes";

if($value =~ /^$allowed$/){
        print (($escape eq "no") ? $value : quotemeta($value));
}else{
        print "Fail!";
}
print "\n";
[download]

When I call this script through a webbrowser it works.. and does not give the error that occurred earlier.

Perhaps the XML::Simple module effects the behaviour in some way ?

Thanks again,
- Pitr