Peers keep contacting me

From VuzeWiki

With any BitTorrent client, you are connected to at least one tracker (either a central tracker server or a distributed tracking system). The tracker stores your IP address and port, and passes it to other peers. Similarly, you get information about other seeds/peers from the tracker.

Other clients can obtain your IP address and port from the tracker, but may not use it right away. Your client will tell the tracker when you log off, but other clients may try to contact you before being notified by the tracker.

• Providing the peer has a correctly beahving client, it will stop the contacts when the tracker lets everyone know you have gone, or when the remote peer gives up after several minutes.
• It is also possible that they have been told by the tracker that you are no longer connected, but due to a buggy or rogue client they are ignoring this.

In addition, many bittorrent clients save information about active peers when stopping, and then use the stored information to speed up launch next time. Thus, a client may have stored your address a few hours/days/weeks earlier and then uses it later.

Read the Azureus FAQ