Check the ID used when the MDG is generated.
The ID must be the same name as the name used in the MDG packages, for example, if using the Model Wizard to create an MDG project browser structure, you are prompted for a name, let's say you entered MYMDG, this name is then used throughout the package structure for the MDG model.
When generating the MDG ensure that you use MYMDG as the ID, then all should be OK.
Once more thing, the ID cannot be more than 12 characters, so when choosing a name for the MDG bear this in mind.
Hope this helps
Phil