If I have any running torrent client on port 6881, when I start ktorrent it display me following message:

"Specified port (6881) is unavailable or in use by another application. KTorrent is bound to port 6882."

But when I try to download a torrent I found that in request to tracker it use port=6881.

What version are you using ?

I think I found where is the problem.

In the constructor of the KTorrent class is created the KTorrentCore obeject.
In the constructor of the KTorrentCore is set the new port and is displayed warning message.
But after creation of m_core object in the contructor of the KTorrent class is invoked function applySettings.
This function set the port to its default value:
m_core->changePort(Settings::port());

George wrote:What version are you using ?

SVN code from 29.10.2005

You are right, it's fixed now, still need to commit it.