thank you tye, that was extremely helpful. seems I had an issue with a blank string being converted to a hash somewhere in an XML parsing phase, which was later cast to a string (which seemed to make perl guess it was a UTF8 one). several concatenations later what looked like a nice plan ascii string, actually wasn't. the solution? specify my input more rigorously:

  if($options->{'customerpass'} && (ref $options->{'customerpass'} ne 
+"HASH")){
    $options->{'customerpass'} = encode("iso-8859-1", $options->{'cust
+omerpass'});
  }else{
    $options->{'customerpass'} = '';
  }
[download]

leaves nothing to guess work and fixed my problem. (this call to encode ( use Encode; ) basically says (I think), 'whatever it looks like, this string is latin1 ascii, end of story.' no more utf8 expansion!)
thanks for the help!