Version:            (using KDE 4.1.1)
OS:                Linux
Installed from:    SuSE RPMs

I tested it on the calendar from Trac project itself: http://trac.edgewall.org/roadmap?format=ics
The calendar was added through System settings>Advanced>KDE Resources as "Calendar in remote file"

At first korganizer displays the events correctly, but crashes, when I click the close button. 

It might maybe be similar to bug 158220

Here is the backtrace:

Application: KOrganizer (korganizer), signal SIGSEGV
[?1034h(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb55818e0 (LWP 20975)]
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[KCrash handler]
#6  0xb5b350f8 in ?? () from /lib/libc.so.6
#7  0xb5b37265 in ?? () from /lib/libc.so.6
#8  0xb5b3911c in malloc () from /lib/libc.so.6
#9  0xb6bcd9ad in qMalloc () from /usr/lib/libQtCore.so.4
#10 0xb6bd5fa3 in QByteArray::resize () from /usr/lib/libQtCore.so.4
#11 0xb6c51943 in QIODevicePrivate::QIODevicePrivate ()
   from /usr/lib/libQtCore.so.4
#12 0xb6c4a64f in ?? () from /usr/lib/libQtCore.so.4
#13 0xb6c4aa03 in QFile::QFile () from /usr/lib/libQtCore.so.4
#14 0xb795e371 in KRES::IdMapper::load () from /usr/lib/libkresources.so.4
#15 0xb60730b0 in KCal::ResourceCached::loadFromCache ()
   from /usr/lib/libkcal.so.4
#16 0xb3d11c80 in KCal::ResourceRemote::slotLoadJobResult ()
   from /usr/lib/libkcal_resourceremote.so.4
#17 0xb3d127a1 in KCal::ResourceRemote::qt_metacall ()
   from /usr/lib/libkcal_resourceremote.so.4
#18 0xb6cbe45a in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#19 0xb6cbe9d2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#20 0xb6ee5393 in KJob::result () from /usr/lib/libkdecore.so.5
#21 0xb6ee5832 in KJob::emitResult () from /usr/lib/libkdecore.so.5
#22 0xb75ce0d0 in KIO::FileCopyJob::slotResult () from /usr/lib/libkio.so.5
#23 0xb75ce84f in KIO::FileCopyJob::qt_metacall () from /usr/lib/libkio.so.5
#24 0xb6cbe45a in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#25 0xb6cbe9d2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#26 0xb6ee5393 in KJob::result () from /usr/lib/libkdecore.so.5
#27 0xb6ee5832 in KJob::emitResult () from /usr/lib/libkdecore.so.5
#28 0xb75c5155 in KIO::SimpleJob::slotFinished () from /usr/lib/libkio.so.5
#29 0xb75c5ce3 in KIO::TransferJob::slotFinished () from /usr/lib/libkio.so.5
#30 0xb75c6d6b in KIO::TransferJob::qt_metacall () from /usr/lib/libkio.so.5
#31 0xb6cbe45a in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#32 0xb6cbe9d2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#33 0xb766fad7 in KIO::SlaveInterface::finished () from /usr/lib/libkio.so.5
#34 0xb76725ef in KIO::SlaveInterface::dispatch () from /usr/lib/libkio.so.5
#35 0xb7670377 in KIO::SlaveInterface::dispatch () from /usr/lib/libkio.so.5
#36 0xb7662f80 in KIO::Slave::gotInput () from /usr/lib/libkio.so.5
#37 0xb76632f3 in KIO::Slave::qt_metacall () from /usr/lib/libkio.so.5
#38 0xb6cbe45a in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#39 0xb6cbe9d2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#40 0xb7594b87 in KIO::Connection::readyRead () from /usr/lib/libkio.so.5
#41 0xb75965c2 in ?? () from /usr/lib/libkio.so.5
#42 0xb7596c16 in KIO::Connection::qt_metacall () from /usr/lib/libkio.so.5
#43 0xb6cb939b in QMetaCallEvent::placeMetaCall () from /usr/lib/libQtCore.so.4
#44 0xb6cbaf31 in QObject::event () from /usr/lib/libQtCore.so.4
#45 0xb6239ecc in QApplicationPrivate::notify_helper ()
   from /usr/lib/libQtGui.so.4
#46 0xb624031e in QApplication::notify () from /usr/lib/libQtGui.so.4
#47 0xb737e80d in KApplication::notify () from /usr/lib/libkdeui.so.5
#48 0xb6cacbc1 in QCoreApplication::notifyInternal ()
   from /usr/lib/libQtCore.so.4
#49 0xb6cad481 in QCoreApplicationPrivate::sendPostedEvents ()
   from /usr/lib/libQtCore.so.4
#50 0xb6cad61d in QCoreApplication::sendPostedEvents ()
   from /usr/lib/libQtCore.so.4
#51 0xb62c400f in ?? () from /usr/lib/libQtGui.so.4
#52 0xb6cab33a in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#53 0xb6cab4fa in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#54 0xb6cad6dd in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#55 0xb6239d47 in QApplication::exec () from /usr/lib/libQtGui.so.4
#56 0x0804ed60 in _start ()
#0  0xffffe430 in __kernel_vsyscall ()

Tell me if I need to install any additional packages to get more debugging info (there was no kde4-korganizer-debuginfo in suses repos)