Version:           4.2.3 (KDE 4.2.3) (using 4.2.3 (KDE 4.2.3), Gentoo)
Compiler:          x86_64-pc-linux-gnu-gcc
OS:                Linux (x86_64) release 2.6.28-gentoo-r6

Steps to reproduce:

1) Open konqueror
2) Go to google.de
3) Start typing in some expression
4) Wait until the suggested search terms appear
5) Close konqueror via CTRL+Q
6) See konqueror crash with the backtrace below.

I think I've seen the KHTMLGlobal::finalCheck thing already somewhere, but a quick search for this backtrace only resulted in reports that were closed back in 2008, so I open a new report...

Backtrace:
#0  0x00007f33bbe9f235 in raise () from /lib/libc.so.6
No symbol table info available.
#1  0x00007f33bbea0753 in abort () from /lib/libc.so.6
No symbol table info available.
#2  0x00007f33bbe980e9 in __assert_fail () from /lib/libc.so.6
No symbol table info available.
#3  0x00007f33b39dce31 in KHTMLGlobal::finalCheck () at /var/tmp/portage/kde-base/kdelibs-4.2.3/work/kdelibs-4.2.3/khtml/khtml_global.cpp:258
        __PRETTY_FUNCTION__ = "static void KHTMLGlobal::finalCheck()"
#4  0x00007f33b036c878 in ~KHTMLFactory (this=0x131b770) at /var/tmp/portage/kde-base/kdelibs-4.2.3/work/kdelibs-4.2.3/khtml/khtml_factory.cpp:35
No locals.
warning: (Internal error: pc 0x7f33bef45be8 in read in psymtab, but not in symtab.)

warning: (Internal error: pc 0x7f33bef45be8 in read in psymtab, but not in symtab.)

#5  0x00007f33bef45be9 in ~FactoryHash (this=0xcb85b0) at /usr/include/qt4/QtCore/qalgorithms.h:352
warning: (Internal error: pc 0x7f33bef45be8 in read in psymtab, but not in symtab.)

No locals.
#6  0x00007f33bef4515a in destroy () at /var/tmp/portage/kde-base/kdelibs-4.2.3/work/kdelibs-4.2.3/kdecore/util/klibrary.cpp:97
        x = (FactoryHash *) 0xcb85b0
#7  0x00007f33bbea1ddd in exit () from /lib/libc.so.6
No symbol table info available.
#8  0x00007f33bbe8b48d in __libc_start_main () from /lib/libc.so.6
No symbol table info available.
#9  0x00000000004008f9 in _start ()
No symbol table info available.