Change the "Specific Version" Attribute isn't a wise solution.
The linked version should have passed the subsonic unit tests, so it should be ok.
From my own experience I know that mysql sometimes changes the behaviour of the assembly (e.g. a returnvalue 0 or 1 suddenly changes to true/false) that's why we are stuck with an old 5.1.2.2 version (we have no unit test's ;( for our old core)
Best Answer
This is a bug in the zip file distribution. It has several copies of 2.1.1.0. It is not fine. 2.2.0 is in the root of the zip distribution, use that.