This may be a silly question, but is there anyone trying to download from you? It's just that I can't see any torrents there, so I assume no one else can...hence nobody will be downloading (I may be wrong).
Usually clients give a reason for no seeding (e.g. Azureus has little smiley faces which, when hovered over, give information. There is also a status column, again in Azureus.) What client are you using?