Version:           3.5.1 (using KDE 3.5.1, Kubuntu Package 4:3.5.1-0ubuntu5 dapper)
Compiler:          Target: i486-linux-gnu
OS:                Linux (i686) release 2.6.15-15-686

I managed to crash konqueror by only using the BTS. No KParts and no other extraordinary things done in that konqueror instance. Max tab usage was around 10, ca. 5 tabs open when it crashed.

Backtrace follows:

Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread 915973824 (LWP 28415)]
[KCrash handler]
#6  0x369bae84 in pthread_mutex_lock ()
   from /lib/tls/i686/cmov/libpthread.so.0
#7  0x37e2174e in pthread_mutex_lock () from /lib/tls/i686/cmov/libc.so.6
#8  0x36f57a3c in XUnlockDisplay () from /usr/lib/libX11.so.6
#9  0x36f7520d in XrmDestroyDatabase () from /usr/lib/libX11.so.6
#10 0x36f59b14 in _XFreeDisplayStructure () from /usr/lib/libX11.so.6
#11 0x36f46427 in XCloseDisplay () from /usr/lib/libX11.so.6
#12 0x3723508a in qt_cleanup () from /usr/lib/libqt-mt.so.3
#13 0x372b7f5e in QApplication::~QApplication () from /usr/lib/libqt-mt.so.3
#14 0x37947428 in ~KApplication (this=0x3f8df94c) at kapplication.cpp:1655
#15 0x368348fb in kdemain () from /usr/lib/libkdeinit_konqueror.so
#16 0x37fbe4f4 in kdeinitmain () from /usr/lib/kde3/konqueror.so
#17 0x0804e00f in launch (argc=2, _name=0x81209ec "konqueror", 
    args=0x81209ff "\001", cwd=0x0, envc=1, envs=0x8120a10 "", 
    reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x46534e41 <Address 0x46534e41 out of bounds>)
    at kinit.cpp:637
#18 0x0804e6b3 in handle_launcher_request (sock=8) at kinit.cpp:1203
#19 0x0804ec3d in handle_requests (waitForPid=0) at kinit.cpp:1404
#20 0x0804fd03 in main (argc=2, argv=0x3f8e0484, envp=0x46534e41)
    at kinit.cpp:1848
#21 0x37d5fea2 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#22 0x0804b7e1 in _start () at ../sysdeps/i386/elf/start.S:119