New Direct Song Tracks in old music packs?

Having recently changed my computer, I have had to rerun all the DS downloaders to get my musics back, and lo and behold, I find that I have 4 new tracks in the original Prophecies score - all denoted with an "a" (ie there was always a track 3, now theres a track 3 and a track 3a).
When were these added, anyone know? Did I miss a memo or something? If I hadn't changed PC, I would never have got these tracks... and I'd like to be confident that I wont miss any more.

Those "a" tracks are what came with Guild Wars Special Edition bonus music key thingy.
Perhaps you forgot to download that last time?