To the best of my knowledge, Adobe decided not to give that away any more. We had the page posted here for the entire CS-2 suite, plus Premiere.
Now the bookmark goes to a log in page.
It's only a guess, but Adobe may have changed the serial. I tried to link the the Adobe download page for someone who was still running CS-1 (PS-7?, and it was unavailable without login.. They've apparently tightened up access.
I simply don't know what affect that may have on copies in the wild.
They might have cranked up their activation servers again. Only God knows.
It might be something different, but that's all I've got.