only specific CC's can heal with IB, such as Raphus's priest CC (might be highly outdated) and i can imagine that Singular should work but last i head was Apoc has completlt re-writting it but the old SVN revision's should work.
PS. if your trying to use IB with cata dungeon's dont bother, use LazyRaider and manually controll your alt you will have a higher success rate.