After 10 mins into the Blitzball? Hmm... No-one else has had problems... Try looking at the DVDs surface for scratches. Also is it a new PS2?
I have a problem with my FFX game.. I've pretty much done everything bar killing off Dark Valefor... The game crashes 100% when I visit Besaid Temple to kill it >_< He's the only Dark Aeon left to kill... Very annoying >_<