christian, i've justed looked through some records and couldn't find something noticeable ... as an example from the server logs for your requests: 2006-08-19 16:34:01 MH_USA-Today.mp3 1926545 Bytes 7188 ms - this is ~260 kB/s (= speed the server delivered the file).
are there any proxy servers, firewalls, ect in the game?
the available bandwidth is 100Mbit and the highest value ever reached was 24 Mbit (during bonus-files downloads), so there should be pretty much headroom left ...
it seems you're on a dynamic IP-address, so you could make a traceroute to vsl.co.at (using network utility) and email me the result to have a look for possible reasons.
christian