MIME::EncWords charset param

hi,

I'm having difficulty getting MIME::EncWords to ouput an encoded,
single-byte value; it always seems to ouput the double-byte (unicode)
value rather than the iso value, for example :

$encoded = encode_mimewords ( "á", Encoding=>"Q", Charset=>"ISO-8859-1");

$encoded has value : =?ISO-8859-1?Q?á?=

.... shouldn't this be : =?ISO-8859-1?Q?=E1?=
?


If instead :
$encoded = encode_mimewords ( "á", Encoding=>"Q", Charset=>"UTF-8");

....I would then expect $encoded to have the value =?UTF-8?Q?á?=
(which it does).


Am i mis-interpreting something?
I've just downloaded a lot of the pre-requisite MIME modules, so they
should be the most recent versions.

tia,
mags.