Well, I've had a lot of experience with swap magic and disc read errors.
First, I usually only had problems like this with back-ups (burned) discs. As its an import, you shouldn't have this problem, but just to be safe I'll say that this problem usually comes with using low quality media, as in Staples brand dvds or something along those lines.
But the other time I've had this kind of problem is a much harder fix. If your PS2 is old, or you've just been using Swap Magic alot, the disc read laser can burn out very quickly. If you've noticed your region games booting slower then this is likely the cause. To fix this requires either getting a new laser or just a new PS2, I'd recommend the second if you really want to play this game, or any more PS2 games for that matter.
Hope this helped!
If you get any more information, I might be able to help you more, so feel free to PM me.