Backtrace from the first crash:

#0  0xb759b6a8 in strcmp () from /lib/tls/i686/cmov/libc.so.6
(gdb) bt
#0  0xb759b6a8 in strcmp () from /lib/tls/i686/cmov/libc.so.6
#1  0xb789e034 in IA__g_str_equal (v1=0x74, v2=0x8489608) at gstring.c:77
#2  0xb7875176 in IA__g_hash_table_lookup (hash_table=0x8169900, key=0x8489608) at ghash.c:240
#3  0xb6f10e73 in ORBit_handle_request (orb=0x8195e30, recv_buffer=0x8342b20) at orbit-adaptor.c:192
#4  0xb6efa077 in giop_connection_handle_input (lcnx=0x8470c00) at giop-recv-buffer.c:1288
#5  0xb6f17a1d in link_connection_io_handler (gioc=0x0, condition=<value optimized out>, data=0x8470c00)
    at linc-connection.c:1417
#6  0xb6f1a9ce in link_source_dispatch (source=0x848b000, callback=0xb6f17940 <link_connection_io_handler>, 
    user_data=0x8470c00) at linc-source.c:159
#7  0xb7881802 in IA__g_main_context_dispatch (context=0x848bf28) at gmain.c:2045
#8  0xb78847df in g_main_context_iterate (context=0x848bf28, block=1, dispatch=1, self=0x848b5a0) at gmain.c:2677
#9  0xb7884b89 in IA__g_main_loop_run (loop=0x848bdd0) at gmain.c:2881
#10 0xb6f167e0 in link_io_thread_fn (data=0x0) at linc.c:396
#11 0xb789f38f in g_thread_create_proxy (data=0x848b5a0) at gthread.c:553
#12 0xb781e504 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#13 0xb75fc51e in clone () from /lib/tls/i686/cmov/libc.so.6
(gdb) thread apply all bt

Thread 4 (process 5035):
#0  0xb7e722ea in acommon::FilterMode::MagicString::hasExtension () from /usr/lib/libaspell.so.15
#1  0xb7e02c1b in ?? () from /usr/lib/libaspell.so.15
#2  0xb7e8d82c in ?? () from /usr/lib/libaspell.so.15
#3  0xb7e8cec4 in ?? () from /usr/lib/libaspell.so.15
#4  0xbffa83f8 in ?? ()
#5  0xb7e838f8 in _fini () from /usr/lib/libaspell.so.15
#6  0xb7e838f8 in _fini () from /usr/lib/libaspell.so.15
#7  0xb7f274ce in _dl_rtld_di_serinfo () from /lib/ld-linux.so.2
#8  0xb755b299 in exit () from /lib/tls/i686/cmov/libc.so.6
#9  0xb75448d4 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#10 0x0806ed21 in _start ()

Thread 3 (process 5045):
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb75f2803 in poll () from /lib/tls/i686/cmov/libc.so.6
#2  0xb7884813 in g_main_context_iterate (context=0x848d930, block=1, dispatch=1, self=0x848d9b0) at gmain.c:2979
#3  0xb7884b89 in IA__g_main_loop_run (loop=0x848b0d0) at gmain.c:2881
#4  0xb7188e62 in e_book_get_type () from /usr/lib/libebook-1.2.so.9
#5  0xb789f38f in g_thread_create_proxy (data=0x848d9b0) at gthread.c:553
#6  0xb781e504 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb75fc51e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 2 (process 7851):
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7821a8c in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb71e1113 in g_cond_timed_wait_posix_impl (cond=0x848ef80, entered_mutex=0x0, abs_time=0x5) at gthread-posix.c:231
#3  0xb7864ad1 in g_async_queue_pop_intern_unlocked (queue=0x8194ec8, try=<value optimized out>, end_time=0xb3e5f434)
    at gasyncqueue.c:341
#4  0xb78a0ee3 in g_thread_pool_thread_proxy (data=0x8194e90) at gthreadpool.c:220
#5  0xb789f38f in g_thread_create_proxy (data=0x8189300) at gthread.c:553
#6  0xb781e504 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb75fc51e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (process 5047):
#0  0xb759b6a8 in strcmp () from /lib/tls/i686/cmov/libc.so.6
#1  0xb789e034 in IA__g_str_equal (v1=0x74, v2=0x8489608) at gstring.c:77
#2  0xb7875176 in IA__g_hash_table_lookup (hash_table=0x8169900, key=0x8489608) at ghash.c:240
#3  0xb6f10e73 in ORBit_handle_request (orb=0x8195e30, recv_buffer=0x8342b20) at orbit-adaptor.c:192
#4  0xb6efa077 in giop_connection_handle_input (lcnx=0x8470c00) at giop-recv-buffer.c:1288
#5  0xb6f17a1d in link_connection_io_handler (gioc=0x0, condition=<value optimized out>, data=0x8470c00)
    at linc-connection.c:1417
#6  0xb6f1a9ce in link_source_dispatch (source=0x848b000, callback=0xb6f17940 <link_connection_io_handler>, 
    user_data=0x8470c00) at linc-source.c:159
#7  0xb7881802 in IA__g_main_context_dispatch (context=0x848bf28) at gmain.c:2045
---Type <return> to continue, or q <return> to quit---
#8  0xb78847df in g_main_context_iterate (context=0x848bf28, block=1, dispatch=1, self=0x848b5a0) at gmain.c:2677
#9  0xb7884b89 in IA__g_main_loop_run (loop=0x848bdd0) at gmain.c:2881
#10 0xb6f167e0 in link_io_thread_fn (data=0x0) at linc.c:396
#11 0xb789f38f in g_thread_create_proxy (data=0x848b5a0) at gthread.c:553
#12 0xb781e504 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#13 0xb75fc51e in clone () from /lib/tls/i686/cmov/libc.so.6