If you set "Link->X = 0" (or move him with scripts) while refilling hearts the screen just freezes, forcing a quit->continue.
Fairy ring freeze.
If I'm not mistaken (bear with me, I'm descrbing something from 2.5 RC1 so it may not still exist), moving Link at all (with or without scripts) locks him out of his controls until he is warped using the Level 4 cheat.
Ugh, horribly ugly stuff. This should be fixed now. I just hope I didn't break something in the process.