I don't thing it's a header problem because the OpenGL headers v1.0 wich i'm using is included with delphi. The Internal Error is wery strange, need to get a copy of d5 and test it out. Going to look trough all my uses etc and remove al unused and wrong includes, hopefully this gets rid of many of these dumb errors.

Have patience

Fixed the D5 error, i never used the function so just deleted it and the assosiated property, will upload a new version tomorrow. it's midnight here now, soon time to sleep =)