Version:           1.0.1 (using KDE KDE 3.5.7)
Installed from:    Debian testing/unstable Packages
Compiler:          4.1.2 
OS:                Linux

This does not happen always, but is quite frequenty for me. After DVD burn is successfully complete and k3b is about to start verification (but the disk has not been ejected yet), k3b enters endless loop (starts using 100% cpu), which makes my PC extremely unresponsive until I eject DVD disk manually. Then k3b still keeps using 100% cpu (k3b process dialog says "Checking medium"), but I now can attach gdb to the running k3b process. Below is the backtrace I get (sorry that without debugging symbols. I'll try get a better one next time):

Program received signal SIGINT, Interrupt.
0x00000000004ab630 in QValueListPrivate<K3bDevice::Track>::at ()
(gdb) bt
#0  0x00000000004ab630 in QValueListPrivate<K3bDevice::Track>::at ()
#1  0x00002b229556ca6f in K3bVerificationJob::readTrack () from /usr/lib/libk3b.so.3
#2  0x00002b229556d2b3 in K3bVerificationJob::slotDiskInfoReady () from /usr/lib/libk3b.so.3
#3  0x00002b229556d464 in K3bVerificationJob::qt_invoke () from /usr/lib/libk3b.so.3
#4  0x00002b229842fc2e in QObject::activate_signal (this=0x1541e00, clist=0x15ac400, o=0x7fff15b578b0) at kernel/qobject.cpp:2356
#5  0x00002b2295536762 in K3bDevice::DeviceHandler::finished () from /usr/lib/libk3b.so.3
#6  0x00002b2295536c5c in K3bDevice::DeviceHandler::customEvent () from /usr/lib/libk3b.so.3
#7  0x00002b229842f36f in QObject::event (this=0x1541e00, e=0x1593eb0) at kernel/qobject.cpp:755
#8  0x00002b22983cb26a in QApplication::internalNotify (this=0x7fff15b5a810, receiver=0x1541e00, e=0x1593eb0) at kernel/qapplication.cpp:2635
#9  0x00002b22983cd014 in QApplication::notify (this=0x7fff15b5a810, receiver=0x1541e00, e=0x1593eb0) at kernel/qapplication.cpp:2358
#10 0x00002b2297292438 in KApplication::notify (this=0x7fff15b5a810, receiver=0x1541e00, event=0x1593eb0)
    at /build/buildd/kdelibs-3.5.7.dfsg.1/./kdecore/kapplication.cpp:550
#11 0x00002b229835e802 in QApplication::sendEvent (receiver=0x1541e00, event=0x1593eb0) at ../include/qapplication.h:520
#12 0x00002b22983cc27d in QApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qapplication.cpp:3299
#13 0x00002b22983cc375 in QApplication::sendPostedEvents () at kernel/qapplication.cpp:3210
#14 0x00002b2298371809 in QEventLoop::processEvents (this=0x892f30, flags=4) at kernel/qeventloop_x11.cpp:144
#15 0x00002b22983e47f6 in QEventLoop::enterLoop (this=0x892f30) at kernel/qeventloop.cpp:198
#16 0x000000000047d4ae in ?? ()
#17 0x000000000052408a in ?? ()
#18 0x000000000054d130 in ?? ()
#19 0x0000000000488462 in ?? ()
#20 0x0000000000488aaa in ?? ()
#21 0x0000000000522e2d in ?? ()
#22 0x000000000054c300 in ?? ()
#23 0x00002b229842fc2e in QObject::activate_signal (this=0x163b190, clist=0x1610790, o=0x7fff15b58700) at kernel/qobject.cpp:2356
#24 0x00002b22984307be in QObject::activate_signal (this=0x163b190, signal=4) at kernel/qobject.cpp:2325
#25 0x00002b22987a5447 in QButton::clicked (this=0x163b190) at .moc/debug-shared-mt/moc_qbutton.cpp:152
#26 0x00002b22984c9bdf in QButton::mouseReleaseEvent (this=0x163b190, e=0x7fff15b58d40) at widgets/qbutton.cpp:836
#27 0x00002b22984641d2 in QWidget::event (this=0x163b190, e=0x7fff15b58d40) at kernel/qwidget.cpp:4702
#28 0x00002b22983cb26a in QApplication::internalNotify (this=0x7fff15b5a810, receiver=0x163b190, e=0x7fff15b58d40) at kernel/qapplication.cpp:2635
#29 0x00002b22983cd3e9 in QApplication::notify (this=0x7fff15b5a810, receiver=0x163b190, e=0x7fff15b58d40) at kernel/qapplication.cpp:2421
#30 0x00002b2297292438 in KApplication::notify (this=0x7fff15b5a810, receiver=0x163b190, event=0x7fff15b58d40)
    at /build/buildd/kdelibs-3.5.7.dfsg.1/./kdecore/kapplication.cpp:550
#31 0x00002b229835e874 in QApplication::sendSpontaneousEvent (receiver=0x163b190, event=0x7fff15b58d40) at kernel/qapplication.h:523
#32 0x00002b229835d49f in QETWidget::translateMouseEvent (this=0x163b190, event=0x7fff15b592e0) at kernel/qapplication_x11.cpp:4301
#33 0x00002b229835b8ff in QApplication::x11ProcessEvent (this=0x7fff15b5a810, event=0x7fff15b592e0) at kernel/qapplication_x11.cpp:3478
#34 0x00002b22983718ba in QEventLoop::processEvents (this=0x892f30, flags=4) at kernel/qeventloop_x11.cpp:192
#35 0x00002b22983e47f6 in QEventLoop::enterLoop (this=0x892f30) at kernel/qeventloop.cpp:198
#36 0x00000000004882dc in ?? ()
#37 0x0000000000512d36 in ?? ()
#38 0x0000000000521c80 in ?? ()
#39 0x0000000000512f8d in ?? ()
#40 0x00000000005194f9 in ?? ()
#41 0x00002b229842fc2e in QObject::activate_signal (this=0x2aaaac1a2e00, clist=0x2aaaac0e16d0, o=0x7fff15b597a0) at kernel/qobject.cpp:2356
#42 0x00002b22984307be in QObject::activate_signal (this=0x2aaaac1a2e00, signal=2) at kernel/qobject.cpp:2325
#43 0x00002b229697cdfc in KAction::qt_invoke (this=0x2aaaac1a2e00, _id=12, _o=0x7fff15b598e0) at ./kaction.moc:215
#44 0x00002b229842fc2e in QObject::activate_signal (this=0x2aaaac0d3510, clist=0x2aaaac302ca0, o=0x7fff15b598e0) at kernel/qobject.cpp:2356
#45 0x00002b22984307be in QObject::activate_signal (this=0x2aaaac0d3510, signal=4) at kernel/qobject.cpp:2325
#46 0x00002b22987a5447 in QButton::clicked (this=0x2aaaac0d3510) at .moc/debug-shared-mt/moc_qbutton.cpp:152
#47 0x00002b22984c9bdf in QButton::mouseReleaseEvent (this=0x2aaaac0d3510, e=0x7fff15b59f20) at widgets/qbutton.cpp:836
#48 0x00002b22984641d2 in QWidget::event (this=0x2aaaac0d3510, e=0x7fff15b59f20) at kernel/qwidget.cpp:4702
#49 0x00002b22983cb26a in QApplication::internalNotify (this=0x7fff15b5a810, receiver=0x2aaaac0d3510, e=0x7fff15b59f20) at kernel/qapplication.cpp:2635
#50 0x00002b22983cd3e9 in QApplication::notify (this=0x7fff15b5a810, receiver=0x2aaaac0d3510, e=0x7fff15b59f20) at kernel/qapplication.cpp:2421
#51 0x00002b2297292438 in KApplication::notify (this=0x7fff15b5a810, receiver=0x2aaaac0d3510, event=0x7fff15b59f20)
    at /build/buildd/kdelibs-3.5.7.dfsg.1/./kdecore/kapplication.cpp:550
#52 0x00002b229835e874 in QApplication::sendSpontaneousEvent (receiver=0x2aaaac0d3510, event=0x7fff15b59f20) at kernel/qapplication.h:523
---Type <return> to continue, or q <return> to quit---
#53 0x00002b229835d49f in QETWidget::translateMouseEvent (this=0x2aaaac0d3510, event=0x7fff15b5a4c0) at kernel/qapplication_x11.cpp:4301
#54 0x00002b229835b8ff in QApplication::x11ProcessEvent (this=0x7fff15b5a810, event=0x7fff15b5a4c0) at kernel/qapplication_x11.cpp:3478
#55 0x00002b22983718ba in QEventLoop::processEvents (this=0x892f30, flags=4) at kernel/qeventloop_x11.cpp:192
#56 0x00002b22983e47f6 in QEventLoop::enterLoop (this=0x892f30) at kernel/qeventloop.cpp:198
#57 0x00002b22983e45ff in QEventLoop::exec (this=0x892f30) at kernel/qeventloop.cpp:145
#58 0x00002b22983ccd48 in QApplication::exec (this=0x7fff15b5a810) at kernel/qapplication.cpp:2758
#59 0x000000000046e7d8 in ?? ()
#60 0x00002b229b7498e4 in __libc_start_main () from /lib/libc.so.6
#61 0x0000000000454a29 in ?? ()
#62 0x00007fff15b5ab88 in ?? ()
#63 0x0000000000000000 in ?? ()