This is still happening for me, when requesting JSON on the GeoPlanet API.
I also sometimes get a 400/Bad Request error for a request that was previously returning a 200 status code.
Example:
=> "http://where.yahooapis.com/v1/places.q('London+-++UK')?format=json&appid=MYAPPID"
QUOTE(duzins @ 5 Oct 2012 2:25 PM)
I'm so sorry I missed this!
The main discussion on this was in the Placefinder forum. http://developer.yahoo.com/forum/PlaceFinder-General-Discussion/PlaceFinder-API-v2-released-/1349096254137-b9ba25b6-f983-4fed-afc6-97a35e7fb644
It was an inadvertent switch and when we realized our error, we reverted.
Robyn