Unable to follow programatically but can retweet


Here is the call, all of the authentication is the same as for the retweet call

Follow call

https://api.twitter.com/1.1/friendships/create.json?screen_name=” + screenName + “&user_id=” + id;

Retweet Call

https://api.twitter.com/1.1/statuses/retweet/” + id + “.json”;

Does anybody know why i would get {“errors”:[{“message”:“Could not authenticate you”,“code”:32}]}
for the follow call and not retweet.

Thank you