As Band Aid/ Live Aid became fashionable these days again, I tried to dig into the Song history.
These are the versions known (tnx to the Live Aid Yahoo group members for help):

4 versions of the song Do They Know It's Christmas? were recorded in 1984, and 1 was re-recorded in 1985.

1. Do They Know It's Christmas? 3:54 - This is the one recently released on the Band Aid 20 single

2. Do They Know It's Christmas? (12" Mix) 6:14 - It has the song Do They Know It's Christmas? Intermixed with various artist wishing you a Merry Christmas.

3. Feed the World - 4:17 - This is the track that was intermixed with the 12" mix. They used the Do They Know It's Christmas song as a backing track.

4. Do They Know It's Christmas? - 4:04 - This track is an acoustic version with Midge Ure on guitar and backing vocals, Bob Geldof singing.

5. One Year On - 4:30 - This track was recorded one year after. It includes Bob Geldof and Midge Ure reading off all the items that Band Aid contributed. This track was released on 45 and on the picture disc shaped like africa. The lyrics appear in the last page of the of the Live Aid booklet of your official 4 DVD set.
=============================================

Band Aid II Put out 2 versions in 1989 (edited !!) avaiable on 45, cassette single, and CD.
1. Do they Know It's Chrsitmas? - 4:23
2. Do they Know It's Chrsitmas? (Instrumental- no singing)- 4:21
=============================================

Band Aid 20 or Band Aid 3
There are 4 versions of this CD.
As a single track, with two tracks, and 3 tracks. On the CD with 4 tracks, the 4th track is the track with Paul Young singing a capella.
==============================================

If anyone knows more details ?
And if anyone has versions 3-5 of Band Aid I, all Band Aid II and Paul Young version of Band Aid III to share with fellow uvoxers ??? confused