I have a similar problem when just starting klamav on kubuntu 7.04 (feisty fawn):

The program unknown (klamav) has crashed and issued the signal 11 (SIGSEGV). 

Here is the debug data I get from KDE crashmanager:

(no debugging symbols found)
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
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[Thread debugging using libthread_db enabled]
[New Thread -1242077488 (LWP 7661)]
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[KCrash handler]
#6  0xb7cbf8ca in KHTMLPart::slotFinished () from /usr/lib/libkhtml.so.4
#7  0xb7cedb6f in KHTMLPart::qt_invoke () from /usr/lib/libkhtml.so.4
#8  0xb6b9b9b8 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#9  0xb778a58e in KIO::Job::result () from /usr/lib/libkio.so.4
#10 0xb77ccf6d in KIO::Job::emitResult () from /usr/lib/libkio.so.4
#11 0xb77cd3ce in KIO::SimpleJob::slotFinished () from /usr/lib/libkio.so.4
#12 0xb77cdadd in KIO::TransferJob::slotFinished () from /usr/lib/libkio.so.4
#13 0xb77ccb9a in KIO::TransferJob::qt_invoke () from /usr/lib/libkio.so.4
#14 0xb6b9b88b in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#15 0xb6b9c330 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#16 0xb7785b1c in KIO::SlaveInterface::finished () from /usr/lib/libkio.so.4
#17 0xb77ea970 in KIO::SlaveInterface::dispatch () from /usr/lib/libkio.so.4
#18 0xb77f2f0a in KIO::SlaveInterface::dispatch () from /usr/lib/libkio.so.4
#19 0xb7799e8c in KIO::Slave::gotInput () from /usr/lib/libkio.so.4
#20 0xb77e3410 in KIO::Slave::qt_invoke () from /usr/lib/libkio.so.4
#21 0xb6b9b88b in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#22 0xb6b9c1a2 in QObject::activate_signal () from /usr/lib/libqt-mt.so.3
#23 0xb6f28877 in QSocketNotifier::activated () from /usr/lib/libqt-mt.so.3
#24 0xb6bbe44a in QSocketNotifier::event () from /usr/lib/libqt-mt.so.3
#25 0xb6b32a60 in QApplication::internalNotify () from /usr/lib/libqt-mt.so.3
#26 0xb6b3488f in QApplication::notify () from /usr/lib/libqt-mt.so.3
#27 0xb72b3ce2 in KApplication::notify () from /usr/lib/libkdecore.so.4
#28 0xb6ac51e9 in QApplication::sendEvent () from /usr/lib/libqt-mt.so.3
#29 0xb6b24e59 in QEventLoop::activateSocketNotifiers ()
   from /usr/lib/libqt-mt.so.3
#30 0xb6ad9d07 in QEventLoop::processEvents () from /usr/lib/libqt-mt.so.3
#31 0xb6b4d136 in QEventLoop::enterLoop () from /usr/lib/libqt-mt.so.3
#32 0xb6b4cf46 in QEventLoop::exec () from /usr/lib/libqt-mt.so.3
#33 0xb6b34609 in QApplication::exec () from /usr/lib/libqt-mt.so.3
#34 0x08067edb in ?? ()
#35 0xbf8b00d8 in ?? ()
#36 0x00000001 in ?? ()
#37 0x00000001 in ?? ()
#38 0x00000000 in ?? ()

I hope that helps to analyse the problem. I have even tried to reinstall the klamav-package or even the complete clamav-package - but the problem still remained.