It sounds as though you have some type of a firewall blocking your incoming. Be it a softw firewall on your computer or a modem/router firewall (which generally use NAT firewalls.) The only way people can downld from you would be to force push (or whatever it's called.) If you went to your stats, I think you'd find there'd been many attempts to downld from you but the majority were unsuccessful.

I had a similar situation after I started using a modem-router. All of a sudden not many people were downlding from me (rarely in fact.) I eventually discovered my router needed a port to be forwarded (port 6346 opened) & ever since I've had crowds of people queueing up for my files (dare I say it.)