i know exactly why
when you burn it
make sure you name it correctly...lol
i know this kuz i lost my install cd
and i had to bum all the files from people over the internet
and i eventually got the whole thing
then burned it
didnt work
made like 50 more copies
then tried to make one with the name Install
and it worked...try naming it EXPANSION

Congradulations George W. Bush!! you Defeated Afghanistan!! You recieve 5,263,772 exp. and a Mythril Plate Mail!!