Using an enumerated data type defined within a MATLAB package folder with a Simulink.Parameter object

Hi, I am trying to use a Simulink.Parameter object with an enumerated data type in a Simulink model (R2011b). I have attached the files I am using.

In order to reproduce the problem I am facing, please try the following steps:

 1. Extract all files to a single folder (e.g. <ROOT>)
 2. Launch MATLAB R2011b and navigate to this ROOT directory
 3. Type 'init' at the command line. A Simulink.Parameter object called SIMULINKPARAM should be instantiated in the base workspace
 4. Open the included sample.mdl Simulink model, and enter 'SIMULINKPARAM' as the value of the constant block

After entering the value of the constant block, I get the error message shown in the attached file 'screenshot.jpg'.

Is there any reason for this error message to occur? Why is a Simulink.Parameter object with an enumerated datatype throwing this error in Simulink, only when the enumeration is defined inside a package folder?

Regards.