Preface:
1) OpenSUSE 11.2 + KDE 4.5.80 (4.6 beta1) + KT 4.1dev. (last on OpenSUSE repositories)
2) Sorry for my bad English please. I understand English much better than writing
3) About of 100 torrents are seeding.
Problem:
KT eats full one kernel of two on my P4 desktop system. 65 to 95 percents in the one-logged-user configuration.
Mysteriously makes Xorg of second logged user to use the second kernel for about 80% when firefox is running.
If KT window is minimized, CPU using goes down for 50% (~100 torrents, I remember), but CPU using of the second-logged-user still high. Closing KT solves a problem of second-logged-user Xorg high CPU usage.
I use KT from 3.3.1. The 3-thread KT have no problem, but 4.x.x have a growing problem.
I engage to read Firefox and Xorg forums and have tried tips recommended. "No Way". Nothing changed.
I conclude this is a KT problem.

PS: Of course, I used a compiled version of KT like a repo-version. No difference.

PPS: "Do not use KIO", "do not use uTP" were tried to no avail.

Do you know how to use oprofile ?