We have a large Exchange 2003 Organization and it has a RUS policy for each Administrative Group in addition to the default policy, which is actualyl listed as the lowest priority. Could this be left over from previous Exchange versions? Why would there be a separate policy for each Administrative group. Is this by desgin?

Very common in multi-domain environments: http://technet.microsoft.com/en-us/library/bb125071(EXCHG.65).aspx