Looks like it is set up right, and as you said no firewall issue. I would normally say that your ISP has probably started using trafficshaping but you allready mentioned that your friend has the same service.

There are two possibilities that still come to mind regarding your ISP

1. You have a quota on amount of data you get to download/upload during each month and you have exceted that amount this month. This can either be checked by calling up your ISP and asking or you can wait until the start of next month to see if you can download again.

2. They started using portblocking. This can be checked by changing your port (try one between 50.000 and 60.000)