Supersample.SuperCrazy and supersample.SuperCrazy
Is the rumble client case insensitive? It can´t download supersample.SuperCrazy if Supersample.SuperCrazy is already downloaded...
A compatibility failure between the downloaders 'check if jar exists' file checker and the robocode 'load given robot jar' file loader. The former is case insensitive (probably had a good reason for it at the time) where as the latter is not.
Now that I think about it, the former may just be a "check if robot exists in robot database", rather then a file checker.