From wikipedia- there's no citation, so I don't know how reliable it is, but it says:
"The version from the Elevation Tour, featured just The Edge on a Gibson Les Paul Custom playing in a lower key with less wah. Bono did not play guitar on these versions, as he usually performed on the heart-shaped stage in the audience. This version is also notable for its added introduction with Bono singing new lyrics over only Edge's arpeggioed chords. His new lyrics would then involve him reciting parts of the chorus of the song. The Edge did not sing in falsetto during the chorus as he has done on the versions from other tours. This tour also included the first extending ending of the song. The band felt that, while the song was good, they hadn't gotten it exactly right. David Bowie told them, upon hearing it, that it needed to be re-recorded. Bono has also said, "It took us fifteen years to really get it right live," assumingly meaning that the intended product is the version played on the Vertigo Tour."