users/lookup

[Justin]

I'm using the users/lookup.json API and passing a valid list of
user_ids that I retrieve from friends/ids (yes, there are <100).

I keep getting the response: "No user matches for specified terms"
when making the call, even though the list is valid and I have
inspected the request being sent.

Any ideas why this would be happening? The friends/ids call is working
fine authenticated and I am trying to make a similar authenticated GET
call with the users/lookup function.

[Justin]

So it only works with POST for me when using authentication. Not sure
if this is an issue with the API itself.