Update: regarding missing attachments, I seem to be seeing an improvement as I can see some replays attached in posts dated around July 2009, whereas when I checked 2-3 weeks ago I had to go to posts dated at least 2010.
But AFAIK no one has actually heard back from Adam on this, so did it somehow fix itself, and why only partially? Very strange indeed...
[edit: actually, it looks like there may be no set date that determines whether attachments are gone or not. One thread I was looking at lost attachments earlier than July 2009, yet another one lost more until 2010.
So probably nothing changed with regards to the problem.
But at least no mystery after all.]