Here's the backtrace stack:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb5eaab90 (LWP 30333)]
0x00a5d258 in QMetaObject::activate (sender=0x828dfd0, from_signal_index=6, to_signal_index=6, argv=0xb5ea9580) at kernel/qobject.cpp:3080
3080 if ((c->connectionType == Qt::AutoConnection
(gdb) bt
#0 0x00a5d258 in QMetaObject::activate (sender=0x828dfd0, from_signal_index=6, to_signal_index=6, argv=0xb5ea9580) at kernel/qobject.cpp:3080
#1 0x00a5d967 in QMetaObject::activate (sender=0x828dfd0, m=0x80b036c, local_signal_index=2, argv=0xb5ea9580) at kernel/qobject.cpp:3185
#2 0x080a1c78 in UDPClient::debugEvent (this=0x828dfd0, _t1=@0xb5ea95b0) at moc_udpclient.cpp:187
#3 0x0809c99e in UDPClient::logEvent (this=0x828dfd0, event=@0xb5ea9a10, at_debug=3) at udpclient.cpp:138
#4 0x0809d365 in UDPClient::sendRequest (this=0x828dfd0) at udpclient.cpp:238
#5 0x080a21e6 in UDPClient::qt_metacall (this=0x828dfd0, _c=QMetaObject::InvokeMetaMethod, _id=5, _a=0xb5ea9b08) at moc_udpclient.cpp:151
#6 0x00a5d3c8 in QMetaObject::activate (sender=0xb3d00f50, from_signal_index=4, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3111
#7 0x00a5d967 in QMetaObject::activate (sender=0xb3d00f50, m=0xb59aa4, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3185
#8 0x00a679a1 in QSingleShotTimer::timeout (this=0xb3d00f50) at .moc/debug-shared/qtimer.moc:76
#9 0x00a67ade in QSingleShotTimer::timerEvent (this=0xb3d00f50) at kernel/qtimer.cpp:298
#10 0x00a5c43a in QObject::event (this=0xb3d00f50, e=0xb5eaa114) at kernel/qobject.cpp:1073
#11 0x00d51ea9 in QApplicationPrivate::notify_helper (this=0x8173480, receiver=0xb3d00f50, e=0xb5eaa114) at kernel/qapplication.cpp:4057
#12 0x00d52261 in QApplication::notify (this=0xbf957038, receiver=0xb3d00f50, e=0xb5eaa114) at kernel/qapplication.cpp:3604
#13 0x00a44a7c in QCoreApplication::notifyInternal (this=0xbf957038, receiver=0xb3d00f50, event=0xb5eaa114) at kernel/qcoreapplication.cpp:610
#14 0x00d4e381 in QCoreApplication::sendEvent (receiver=0xb3d00f50, event=0xb5eaa114) at ../../include/QtCore/qcoreapplication.h:213
#15 0x00a7e1f5 in QTimerInfoList::activateTimers (this=0x8288f34) at kernel/qeventdispatcher_unix.cpp:572
#16 0x00a7b094 in timerSourceDispatch (source=0x8288f00) at kernel/qeventdispatcher_glib.cpp:164
#17 0x00325372 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#18 0x00328366 in ?? () from /lib/libglib-2.0.so.0
#19 0x003288be in g_main_context_iteration () from /lib/libglib-2.0.so.0
#20 0x00a7aa84 in QEventDispatcherGlib:rocessEvents (this=0x8288dd8, flags={i = -1242914168}) at kernel/qeventdispatcher_glib.cpp:324
#21 0x00a40ef6 in QEventLoop:rocessEvents (this=0xb5eaa31c, flags={i = -1242914100}) at kernel/qeventloop.cpp:149
#22 0x00a41152 in QEventLoop::exec (this=0xb5eaa31c, flags={i = -1242914012}) at kernel/qeventloop.cpp:200
#23 0x009305e5 in QThread::exec (this=0xbf956ea4) at thread/qthread.cpp:487
#24 0x0809fd04 in UDPClientThread::run (this=0xbf956ea4) at udpclient.cpp:488
#25 0x00934d39 in QThreadPrivate::start (arg=0xbf956ea4) at thread/qthread_unix.cpp:189
#26 0x0014e49b in start_thread () from /lib/libpthread.so.0
#27 0x0342842e in clone () from /lib/libc.so.6