Always getting 403 Error on friendship create for some users but not all


I run an automatic follow back application. For certain users I am unable to create a friendship using the Rest API as I get a response code 403 FORBIDDEN for those users. It is the same users every time that for some reason I am unable to make friendship create requests on their behalf.

I have found that if a user deauthorizes my app, I get a 401 response when I try to create a new friendship for that user. So that is not the problem.

Has anyone else seen this? I do not have a problem with OAuth or anything like that as I have no issues making friendship creates for MOST of my users but some of them always return 403. Any thoughts?

Also, I know the users are not hitting their daily follow limit. One particular user who always has this problem has tens of thousands of followers and only follows about 1,500. So I do not believe that is the issue either.