Okay for the life of me I can't find the other thread we had going that was "just" the Shockwave Error. I could have sworn we had a separate thread just for that error, but I guess I'm wrong (or blind

).
This was a very common error back when the June Update happened. There were quite a few of us that were unable to log in at all into BFAHP for the entire month, until they updated the site for the July Update.
There are different Shockwave error messages. If you are getting the "Shockwave Movie Error," the one that tells you there is something wrong with the "movie" so please contact the author, then you are most likely stuck until CN updates the site for Sept. Uninstalling and Installing Shockwave or updating it will do nothing for this kind of error.
If you look back from post #19 of this thread and read on until this page, you'll see what we were experiencing, and possibly you'll find your answer in there. Some posts were merged, so it might not all flow nicely, but at least you'll get the jist of what we figured out.
And, you're right, it IS associated with certain accounts - not all of them. At least the Shockwave Movie Error is. You'll see my experiments and conclusions around page 2 or 3, I don't remember where. Needless to say, it didn't matter where I tried to log in, it wouldn't work for certain accounts we own.
Hope this helps!
~Vicks