basically nowhere msdn has some IIS based docs which are not really helpfull as most of the stuff does not work with this. then on the web there is one or two places which say to provide info but actually their info is really basic.
first, you might try this other one. if the data is long, kixtart string manipulation limits come to play so you can't thus display it. the limit was something like 30k.
with this you can see does it get anything. if it does not, there may be other errors like wrong addy or similar.