Version:           CVS current (using KDE KDE 3.1.2)
Installed from:    SuSE RPMs
Compiler:          g++ (GCC) 3.3 20030226 
OS:          Linux

If I try with current CVS version a xmi file with use case diagrams, all use case symbols have no label text.
Additionally I get a lot of debug messages:
WARNING:  Syncronize classifier code doc:0x99d2838
(I'm not shure if these warnings belong to the problem with use case labels).

I tried to see and change the properties of a use case symbol in a use case diagram
--> umbrello crashed with the following trace:
------------------------------------------------------------------
[New Thread 16384 (LWP 32072)]
0x41097cf7 in waitpid () from /lib/libpthread.so.0
#0  0x41097cf7 in waitpid () from /lib/libpthread.so.0
#1  0x4079ac89 in KCrash::defaultCrashHandler(int) ()
   from /opt/kde3/lib/libkdecore.so.4
#2  0x41096895 in __pthread_sighandler () from /lib/libpthread.so.0
#3  <signal handler called>
#4  0x080f33a6 in UMLObject::getBaseType() const ()
#5  0x0820d39b in ClassGenPage::ClassGenPage(UMLDoc*, QWidget*, UMLObject*) ()
#6  0x0820a29d in ClassPropDlg::setupPages(UMLObject*, bool) ()
#7  0x08209a83 in ClassPropDlg::ClassPropDlg(QWidget*, UMLWidget*) ()
#8  0x080fdb0b in UMLDoc::showProperties(UMLWidget*) ()
#9  0x080e1e27 in UMLWidget::slotMenuSelection(int) ()
#10 0x080e45bc in UMLWidget::qt_invoke(int, QUObject*) ()
#11 0x40b3c8e7 in QObject::activate_signal(QConnectionList*, QUObject*) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#12 0x40b3c9c8 in QObject::activate_signal(int, int) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#13 0x40e48bc0 in QPopupMenu::activated(int) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#14 0x40c2dcfc in QPopupMenu::actSig(int, bool) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#15 0x40c320f7 in QPopupMenu::mouseReleaseEvent(QMouseEvent*) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#16 0x40b72954 in QWidget::event(QEvent*) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#17 0x40adb5f8 in QApplication::internalNotify(QObject*, QEvent*) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#18 0x40adad76 in QApplication::notify(QObject*, QEvent*) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#19 0x40727929 in KApplication::notify(QObject*, QEvent*) ()
   from /opt/kde3/lib/libkdecore.so.4
#20 0x40a7c886 in QETWidget::translateMouseEvent(_XEvent const*) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#21 0x40a79e30 in QApplication::x11ProcessEvent(_XEvent*) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#22 0x40a8f4f2 in QEventLoop::processEvents(unsigned) ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#23 0x40aefb83 in QEventLoop::enterLoop() ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#24 0x40aefa76 in QEventLoop::exec() () from /usr/lib/qt3/lib/libqt-mt.so.3
#25 0x40adb87f in QApplication::exec() () from /usr/lib/qt3/lib/libqt-mt.so.3
#26 0x081180b7 in main ()
#27 0x411f68ae in __libc_start_main () from /lib/libc.so.6
------------------------------------------------------------------
===>
I suspect that this depends on the changes on internal code edit for classes,
as some of the functions in the call stack sounds like class management and since
this error is new since the last changes of around a week ago.

####
You can reproduce it by simply:
a) create new project with one use case 
b) create one use case diagram with the use case of a) (label is correct!!)
c) save - reload
--> use case in diagram has no label any more -> real save/reload problem
d) try to change property
--> CRASH