I concur, it
has changed!
Oddly, I've also noticed that it's different again if downloaded from the UK BC page.
The
US xbox.com BC page says "March 2006 update", the
UK BC page doesn't (phased rollout maybe?).
Further, looking inside the March update zips....
US default.xex downloaded early March = 3,862,528 bytes
US default.xex (downloaded just now, 04/04) = 3,153,920 bytes - So indeed smaller!
UK default.xex (downloaded just now, 04/04) = 3,866,624 bytes - Biggest!
Well spotted Hannard, and certainly interesting.
The file was different last night, which was I last downloaded it. Now I've tried it again and it's a new file! In fact, I know why it's changed. It's a stealth update to enable sound on the PAL version of Star Wars Battlefront 2! And presumably Ninja Gaiden as well.