Kay well here's the deal. You CANNOT PLAY Siren 2 PAL version for a variety of reasons. First off, it's one of those special games too big for a regular dvd (DVD9) so Swap Magic is out out of the question as it only runs DVD5. 2nd off a PAL disc will not run on a US PS2 (duh), and lastly a PAL video signal will not display on our TVs.
My solution: Convert the DVD9 ISO to a DVD5 using special software and put it on a rergular DVD5 disc so swap magic will play it. I heard that using component cables will somehow bypass the PAL signal so it can be displayed on a LCD TV. This is a pain in the ass but I'm gonna give it a try, I'll let you know if it works.