I'm not completely sure of what I am talking about as far as I've never used the API, but you should try to look at the end of the file which generates your XML for a closing '?>'
. If there is this closing PHP marker, remove it and try again you API call...
In Magento, PHP file should never be ended by a closing php marker '?>'
.
edit: as said in comments, also look at spaces before the opening tag '<?php'
.
Hugues ALARY
2010-06-06 11:52:36