right of the bat I have to advice you might have to change your ballast
![Sad :(](./images/smilies/icon_e_sad.gif)
![Rolling Eyes :roll:](./images/smilies/icon_rolleyes.gif)
as to the effect you are getting on the screen if it is fixed by physically manipulating the screen itself, this can be a misalignment with the projector or the screen itself, you mentioned it has been moved around, is the screen perfectly flat? or is it concave at some point???