Version:           0.10.0-beta1 (using 4.1.00 (KDE 4.1.0), Gentoo)
Compiler:          i686-pc-linux-gnu-gcc
OS:                Linux (i686) release 2.6.25-gentoo-r7

I opened digikam, created a new tag, tagged some images with that tag, deleted some tags from some of the images and finally closed digikam. When I closed it, it crashed with the backtrace below. So far I have not been able to reproduce this crash. Also: Digikam does not really seem to be the culprit anyway... Looks to me more like a problem in kdelibs or Qt?

Application: digiKam (digikam), signal SIGABRT
[Thread debugging using libthread_db enabled]
[New Thread 0xb4e3b720 (LWP 582)]
[New Thread 0xad8fcb90 (LWP 637)]
[New Thread 0xb30fbb90 (LWP 617)]
[New Thread 0xb28fab90 (LWP 616)]
[KCrash handler]
#6  0xffffe424 in __kernel_vsyscall ()
#7  0xb5534690 in *__GI_raise (sig=6)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#8  0xb5535ed8 in *__GI_abort () at abort.c:88
#9  0xb556f57d in __libc_message (do_abort=2, 
    fmt=0xb562c960 "*** glibc detected *** %s: %s: 0x%s ***\n")
    at ../sysdeps/unix/sysv/linux/libc_fatal.c:170
#10 0xb55753c4 in malloc_printerr (action=2, 
    str=0xb5629737 "corrupted double-linked list", ptr=0x83fff88)
    at malloc.c:5949
#11 0xb5575664 in malloc_consolidate (av=0xb5647140) at malloc.c:4860
#12 0xb557699f in _int_free (av=0xb5647140, mem=0x85a4a98) at malloc.c:4737
#13 0xb5576d2c in *__GI___libc_free (mem=0x85a4a98) at malloc.c:3625
#14 0xb570860d in operator delete (ptr=0x0)
    at /var/tmp/portage/sys-devel/gcc-4.3.1-r1/work/gcc-4.3.1/libstdc++-v3/libsupc++/del_op.cc:49
#15 0xb674c2c8 in QMapData::continueFreeData (this=0x85a4a98, offset=8)
    at tools/qmap.cpp:86
#16 0xb675abf5 in QMap<int, int>::freeData (this=0x87cd0ac, x=0x85a4a98)
    at ../../include/QtCore/../../src/corelib/tools/qmap.h:599
#17 0xb675bf2b in QVector<QRegExpAutomatonState>::free (this=0x8423c3c, 
    x=0x87ccfd8) at tools/qmap.h:153
#18 0xb675605f in ~QRegExpEngine (this=0x8423c38) at tools/qvector.h:112
#19 0xb675c993 in QCache<QRegExpEngineKey, QRegExpEngine>::trim (
    this=0x83ce3e8, m=86) at tools/qcache.h:75
#20 0xb675cb1c in QCache<QRegExpEngineKey, QRegExpEngine>::insert (
    this=0x83ce3e8, akey=@0x860ea44, aobject=0x860e900, acost=14)
    at tools/qcache.h:189
#21 0xb675676f in invalidateEngine (priv=0x860ea40) at tools/qregexp.cpp:3269
#22 0xb67568b6 in ~QRegExp (this=0xb6b77a5c) at tools/qregexp.cpp:3414
#23 0xb6b0cdc8 in __tcf_6 ()
    at /var/tmp/portage/kde-base/kdelibs-4.1.0/work/kdelibs-4.1.0/kdecore/localization/kuitsemantics.cpp:1488
#24 0xb5537571 in *__GI_exit (status=0) at exit.c:75
#25 0xb552063d in __libc_start_main (main=0x8266080 <main>, argc=5, 
    ubp_av=0xbfa7fcf4, init=0x8294e50 <__libc_csu_init>, 
    fini=0x8294e40 <__libc_csu_fini>, rtld_fini=0xb7f725e0 <_dl_fini>, 
    stack_end=0xbfa7fcec) at libc-start.c:258
#26 0x080a1df1 in _start ()
#0  0xffffe424 in __kernel_vsyscall ()