DWithin Filter

[Miguel Gonçalves]

I am using the WFS DWithin filter to get all the cities in a range of 
1000 meters from a point
using the following request;

http://localhost/cgi-bin/mapserv.exe?MAP=../mymap.map&SERVICE=wfs&VERSION=1.0.0&REQUEST=getFeature&TYPENAME=cities&Filter=
<Filter>
    <DWithin>
        <gml:Point>
        <gml:coordinates>-8.418000,41.539600</gml:coordinates>
        </gml:Point>
        <Distance units='m'>1000</Distance>
    </DWithin>
</Filter>

In the results that I obtain the distance of the cities from the point 
is not being accurate.
I believe I am having problems with the units.
Can somebody help me to correct my request?
Beste regards.
Miguel