Post the ones you have noticed being asked a lot here, want to put this up on the WIKI.
I will get us started with what is actually the most frequent anyway.
You have note repeat turned on.
Here's one that made me waste the most amount of time.
The input source isn't turned on in BM3's settings. Input devices aren't turned on by default, output devices are.
This is less of an FAQ and more of a strange occurrence.
Beatmaker 3 was running when the battery went flat, when the iPad tried to restart it automagically tries to restart Beatmaker 3 too, Beatmaker 3 consumes more power than the charger is putting in to the iPad, when the iPad starts, login, double click home button, force quit Beatmaker 3.
Turn MIDI Omni to off in the settings (small cog)
You can't, but there is a partial workaround, just open the pattern helper and drag any source content from one track to any other.
Probably not. Unless you are meticulous with your housekeeping, it's very likely some of your tracks reference trimmed samples and audio recordings that are stored in Unsaved Sessions. You have been warned!