While upgrading to the full 3.6 release:

	Error: error occured retrieving 
http://www.ira.uka.de/~marcus/System-Benchmarking.st:
	Server www.ira.uka.de is not responding

Of course, this can happen. But the error should be caught and this 
package should simply be skipped, perhaps with a notice afterwards 
("loading package ... failed, try again later by doing ...").

IMHO this is a critical error, as it will severely confuse someone who 
tries to get a full image (who likely is no hard-core squeaker).

-- 
    Bert