I bought the game (Trinity) and, when I got it, I put it in my CD tray and...nothing. The computer makes the first noise it usually makes when a new CD/DVD gets put in, but nothing follows (usually there is a loudish whir as the CD/DVD loads up and when it's read generally).
I sent it back and got the game somewhere else. I put it in and the same happened.
My computer meets all the minimum requirements and I think all the recommended requirements. It reads and writes DVDs, and other DVD games read perfectly (Sims 3 and Star Wars Best of PC for example).
EDIT: ONE of the Star Wars Best of PC DVDs reads fine, the other one takes a few tries, the other one doesn't read (like Trinity). What??? 
My computer is an XP SP3.
What's the dealio? And why have I found no-one else at all on Google specifying this problem? Is it only me? 
Is there a fix? If not, will it work fine if I (am forced to
) buy it here and download it?