Battle / Battles
(I heard Battle, then got confused when reading a description of Battles. At first I just put it down to overzealous journalism)

Q And Not U / Q Without U
(I might be alone in noticing this one)

Nelly Furtado / Nelly
(Once again I wondered where the familiarity was when first hearing Hot In Herre)

The Prodigy / Prodigy
(Not particularly surprising)

Subtle / Subtitle
(Close enough that ATP ended up inadvertantly booking Subtitle, pretty much)

Field / Field Music
(I assumed someone had missed an apostrophe-s. Thankfully never confused with Fieldy's Dreams)

GZA / RZA
(I'd like to know who was named first)

JJ Cale / John Cage
(This one's probably just me being stupid)

John Mayer / John Mayall
(John Mayer's Bluesbreakers?)

Any others?