Luckily, a couple pieces (like me) of the pSX Troubleshooting Team post here on these forums too...
But seriously, problems like this have occurred to a select few people (freezes during gameplay, especially after disc 1). There are two techniques I've discovered that can help get past this problem most of the time.
1) Try using a PAL BIOS. This being a copy-protected game, we have noticed that when they are not patched (and even occasionally when they are), random freezes can occur during gameplay, as well as when it starts. Using a PAL BIOS not only gets past the initial copy-protection screen, but it also has been known to get past these in-game freezes.
2) Try fast-forwarding past the freeze. That doesn't have too high of a success rate, but it's been known to work maybe half the time, depending on the game.
If neither of these work, let us know. Also, might be a good idea to tell which region the game is from. And what BIOS you're using. And are you using the latest version of pSX? Have you tried older versions? Please give the relevant information.