It's not the black cover that's the problem. Which black cover....?
It's the blue/green gasket on the DM controller that fails and lets in water. There was a recall on a run of VIN No.'s to replace the gasket which had been incorrectly fitted at the factory. My '04 bike wasn't within the recall and the gasket was still incorrectly fitted. The DM controller on mine failed about 6 months out of warranty. BMW paid for the part.