Could someone PLEASE tell me what does the Adv. Pack add? I lost all my docs and I really need to know.

Welcome to the forum, che.
If you mean the Bonus CD - then it adds a merchant with uber weapons, located in Kuldahar.

Neuro

<font color=skyblue>The adventure pack is separate from the CD that you get in the Collector's Edition, as I have been told. On the adventure's pack, you get a small subplot...and another area to discover. There are some other minor things as well, such as select musical numbers from the game. It does not have the new merchant location and added items.</font>

I have both of the disks, Because when I went in to the store where I ordered the Collectors Edition to see if it had arrived the NEW kid that had been left in charge said "NO BUT WE HAVE THE ADVENTURE PACKS IN,GO AHEAD AND TAKE ONE THEIR FREE,IF YOU RESERVED A GAME!" so I have both Disks and the only thing different seems to be that the one that came with the game has all the music from the game and the Adventure pack has around 10 cuts everything else is the same. the reason I say this is when I tried to install the one that came with the game after I already loaded the adventure pack CD it said that the adventure section with the CD was already installed but it let me play and save all the new music from the game. so if you have the Adventure pack you should have all the good stuff just short a bunch of 50 second cuts of music.