Description of problem:
In Process Definitions perspective, you can get the Definition Details tab either by clicking the name of the process or by clicking the details button on it's row.
The first way opens the Definition Details tab next to the Process Definitions perspective tab.
The second way opens it over the Process Definitions perspective.

I'd expect the behaviour to be the same for both.

Version-Release number of selected component (if applicable):
6.0 ER2