That seems to be a common mistake, Mike. The Naxos classical music site says:

'Juventino Rosas has received very little musical training, with no study abroad. He remains the definitive Mexican waltz king, with an enviable command of melody and perfect understanding of harmony and rhythm, and above all of the way to give his works an ending of brilliance. The best tribute to his talent is the fact that his most famous waltz, Sobre los olas (On the Waves), has often been attributed to Johann Strauss, confirmed by the European mistake of including this work in concerts of Viennese music in the Old World. Nevertheless Strauss himself would certainly have been happy to own this waltz.'

I read somewhere that Rosas was a native (Indian) Mexican, rather than a European, but Naxos says nothing about it.