I'm also getting different results via SOAP Api compared via bing translator on the web...
as in:
"I see..." -> "Ich sehen" (MS Translator) <-> "Ich verstehe..." (Bing)
and trying to get different available translations results in none beside this one.
and same via direct http/ajax....the browser shows np, but doin either soap/webrequest via c# i always get the wrong translation :-/