If two portlets have the same name and one of them is a graphical portlet than the graphics of this portlet is not available.
example:
both portlets "Test Statistcs Grid" and "Test Statistics Chart" where used in the dashboard-view and got the same name "Test Stats". the grid is displayed without problem but the chart portlet just shows its title but no chart, just the text "[Test Summary graph]". (see attached screenshot)
And if the tilte of the chart portlet gets clicked the test statistcs grid is displayed full size.

either it should be prevented that two (different) portlets get the same name or it should work.