@Deusovi I think the difficulty was good; we only solved this easily as a community effort (Gareth noticed romans, GPR noticed binary, and I noticed permutations, at which point I already had XXD MIDI MIX, but didn't post an answer as I thought it was nonsense).

@ffao: Thank you! (Also, sorry about the error. D: )

Can't do much when even the test solver misses it :P

Yeah, I can't do basic arithmetic either apparently. Note to self: don't make puzzles involving arithmetic anymore.