Regarding 'Samba Nova' - which I saw a few people comment on - the differences are very slight and you'll need a keen ear to here them - but there's definitely a few level and EQ changes that have been done to what we'd heard before.
I thought you said that the vocal track is different. Is it?
Listening to it a few more times:
*The drum loop is lower in the mix
*The vocals sound smoother because of a very analog sounding delay on them that's a tad more noticeable.
*The intro in just guitar/fretless bass/voz (for the first 4 bars) then percussion comes in for the next 4.
*The vocals at the start of the 2nd verse sound different - but i dunno if that a level thing, diferent take or because they're not as wet (with delay) as the old version.
*The harmonic sound things after the guitar solo are louder and the persussion loop is a little lower.