I heard the version as well, and it has zoomed straight into second place (just behind Witless Useless' hymn to a major search engine - I will always love Yahoo) as the worst cover version ever.
I know Cash was old and ill when he made the recording, but his voice sounds dreadful and detracts from one of the most beautiful love songs ever written.
Johnny Cash is a legend, and this detracts from the massive body of fantastic work he created - it's only a blip - but I never ever want to hear it again.