A new version of Cloo has just left the factory.
This release is not backward compatible due to the changes affecting the Read/Write methods of ComputeCommandQueue. The application is now responsible for allocating and freeing memory/GCHandles and passing valid pointers to these methods (see VectorAddTest.cs for an example). Although, in theory it is possible to handle these situations inside Cloo, in practice it involves a lot of possibly unnecessary operations which could hurt the performance of real world applications.
Speaking of which, the raw OpenCL bindings are now public. For those of you living on the edge, this gives you the finest degree of control (or endless headaches if something goes wrong).