Triggering the bug is rather annoying because you either have to wait until a flying ? box with a mega mushroom in it goes to that level, or get far enough in the game to purchase a mega mushroom.
There's a mega mushroom in 1-1.
Yes, but I don't recall seeing this bug on 1-1; although I may not have ground-pounded above the bottom of the screen... I'll check.
You don't need to check, it is in 1-1; I've seen it.
DS GX: Fix T-repeat textures (fixes #577)