I was just listening to Bob Dylan's recent album 'Together Through Life' and there's a track on there called 'My Wife's Home Town' which is basically a re-write of Willie Dixon's 'I Just Want To Make Love To You'. Dylan has done the decent thing and given Dixon a composer's credit and presumably some money will eventually find its way to Mr Dixon's estate.
Willie Dixon and many other blues men have been ripped off by rock musicians for years now. Notable exponents of the blues rip-off are Led Zeppelin whose victims also include Howlin' Wolf and Muddy Waters (Led Zeppelin Vol.2 has some blatant examples). Dixon led the fight back and set up the Blues Heaven Foundation which not only promotes The Blues but also works to secure copyrights and royalties for blues musicians who have been exploited.
Led Zeppelin (and others) have been sued succesfully for millions. Maybe Bob Dylan learned by example!
Footnote: Dylan's next release is to be a Christmas album in which he performs various Christmas standards such as 'Winter Wonderland'. He's donating his artiste's royalties to 'Feeding America', a charity which provides food to starving Americans. I bet you never realised there are starving Americans!