Hello,
When we do an OpenSocial Request for a user's friends, many users show up with hasAppInstalled=false when they do in fact have the application installed.
A specific example:
Our application id is 110096. Getting the first page of users (http://api.msappspace.com/api-v2.svc/json/people/@me/@friends?startIndex=1&count=50&filterBy=all) reports that user 9525754 doesn't have the application installed ("hasAppInstalled":false). But they actually do have the app installed (it even appears on their profile). We also have access to their data through the REST API. Its just this @friends request that is returning buggy data.
We'll be happy to provide more examples to help with this issue.
Thanks!