[NTG-context] Context in Portuguese

Hi ! I've been a Latex user for some time and I'm now trying to use Context to typeset some documents in portuguese using portuguese accentuated characters but I can't seem to get it working. Every time I use an accentuated character it simply doesn't shows up in the document. I'v read the docs but haven't found a solution to the problem. Can someone provide me a simple example on how to do it, or the problem I'm facing has to do with some kind of configuration that has to be done in Context ? I'v been trying to use Context using the tex iso available at pragma's website. Thank you, Miguel Queirós