Today, the first time for at least a week I downloaded Atlanta track and then went to download Le Mans 2004 only to find that no more connections from my IP allowed.
Does this mean I am only allowed to download one file a day/week?
No, that does mean that only one connection at a time is allowed. But because most downloaders don't close their connection even when they are finished you have to wait until the connection time-out is reached.