Try a third ISO?
While that sounds like a harsh reply, I did have problems getting a working copy of the game myself..... I wanted the US version for 480p (to avoid any force progressive problems) and getting a working one was a right arse....
That said, if it's running up to the end of a race, it will probably be something else anyway.... are you using a real memory card or NMM? PAL or NTSC? 1:1, shrunk or extracted? Have you got force progressive on? Using a loader? ....Tried Nintendont with it?