Transposing?

[LadyJazzer]

I downloaded the "Brazilian" set to my iPhone. I've tried changing a few of the tunes I do frequently to different tempos, different numbers of choruses, etc. I noticed that "Triste" is in the key of 'A', and everyone I work with does it in "Bb"...So, I did the following:

Edit | Info | Key Signature | Bb Major | 'Set and Transpose' | Done | Done | Save

No matter what I do, it doesn't change the key to Bb...

(I tried the same process on "Favela", and it worked fine... So, is there something different about "Triste" that it won't let me change the key?)

Thanks!

LJ