I thought that you are generally expected to write your WSDL by hand, that the generators don't work.

I thought so too, which seemed really odd since .NET has the WebMethod attribute which sets up some automagickal WSDL/webservice thing that does what you need to expose your code as a webservice.
Example: Creating web services with .Net and Visual Studio

Example:

[WebMethod]
public string greet( string name ) {
  return "Hello, " + name;
}
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The POD sections that Pod::WSDL looks for are pretty much along the same lines.

=begin WSDL

_IN name $string
_RETURN $string

=cut

sub greet
{
  my ($s, $name) = @_;
  return "Hello, $name!";
}
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I typed cpan SOAP::Lite and it just worked.

If you're using Apache 1.3x that works just fine.