No, there is no free upgrade, in the same way version 1.0.2 became obsolete when 2.0 was released. This is actually true for pretty much every commercial software and even OS versions, e.g. with the exception of security updates Apple doesn't fix any bugs in old OS X versions. Hey, even my car has software bugs, which can be "easily" fixed by buying a 2013 model...
Many error corrections seem to be towards 2.2.1, or even 2.1.3. E.g. download of content didn't exist in 2.1.3, therefore there are no bugs to be fixed. 2.2 has an audio engine that supports multi-cores (= much faster), but it also introduced some bugs, which are getting fixed.