It is a non-linear map which have many paths to take and reach the end. The point is, that you play a map one time and you are happy. Then you have a little break in Portal, because there aren't any new released maps for some time. But the answer is here: play the Deja-Vu again, but choose a different path with different puzzles. You can choose freely the way that is going to lead you to the end. Thats it!
The thread you are attempting to browse is deleted. We recommend you return to Who Am I? and browse the other threads there.
We recommend you return to the forum list and browse the links from there. If the problem persists, contact us with the details.