The day before Yesterday i registered an Application for the website of an costomer.
I filled in all the fields with a red star, and it was succesfully registered.
But when i tried to use it, with the linking code (to register users), it wasn't able to connect to Twitter.
I checked the http code, and it returned 401, so the Authentication Keys where wrong.
I kept checking, changed everyting, but nothing seemed to work.
Today i was still trying to get it working, and decided to fill in the Callback URL at the API page, and then it finally worked.
But acctually it's strange.
My first point is that the Callback URL isn't really the same as Authentication Keys, so it was kind of strange code in this situation.
Second, why isn't there a star at the Callback URL, when it is needed to get the API working.
Since it took me quiet some time to figure this out i hope you can improve this, hoping it won't happen to others!