I am also seeing this error when I right-click on a text file and choose "Send to...".  I am running Ubuntu 6.10.  Here is the output of bug buddy: 

Memory status: size: 64172032 vsize: 0 resident: 64172032 share: 0 rss: 12193792 rss_rlim: 0
CPU usage: start_time: 1170870961 rtime: 0 utime: 33 stime: 0 cutime:30 cstime: 0 timeout: 3 it_real_value: 0 frequency: 0

Backtrace was generated from '/usr/bin/nautilus-sendto'

Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".

[Thread debugging using libthread_db enabled]
[New Thread -1225214288 (LWP 10156)]
[New Thread -1269912672 (LWP 10166)]
[New Thread -1261519968 (LWP 10159)]

0xffffe410 in __kernel_vsyscall ()
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb746434b in __waitpid_nocancel ()
   from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb7f0d1b6 in gnome_gtk_module_info_get () from /usr/lib/libgnomeui-2.so.0
#3  <signal handler called>
#4  0xb7390c2b in strlen () from /lib/tls/i686/cmov/libc.so.6
#5  0xb7363884 in vfprintf () from /lib/tls/i686/cmov/libc.so.6
#6  0xb7381b8c in vasprintf () from /lib/tls/i686/cmov/libc.so.6
#7  0xb74bf8b7 in g_vasprintf () from /usr/lib/libglib-2.0.so.0
#8  0xb74b18a6 in g_strdup_vprintf () from /usr/lib/libglib-2.0.so.0
#9  0xb749ef54 in g_logv () from /usr/lib/libglib-2.0.so.0
#10 0xb749f159 in g_log () from /usr/lib/libglib-2.0.so.0
#11 0xb6e53a3e in add_evolution_contacts_to_model ()
   from /usr/lib/nautilus-sendto/plugins/libnstevolution.so
#12 0xb6e53f5a in add_evolution_contacts_to_model ()
   from /usr/lib/nautilus-sendto/plugins/libnstevolution.so
#13 0x0804a71b in main ()

Thread 3 (Thread -1261519968 (LWP 10159)):
#0  0xffffe410 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb73e7803 in poll () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#2  0xb7499813 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#3  0xb7499b89 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#4  0xb6dede62 in e_book_get_type () from /usr/lib/libebook-1.2.so.9
No symbol table info available.
#5  0xb74b438f in g_thread_create_full () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#6  0xb745d504 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
No symbol table info available.
#7  0xb73f151e in clone () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.

Thread 2 (Thread -1269912672 (LWP 10166)):
#0  0xffffe410 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb73e7803 in poll () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#2  0xb7499813 in g_main_context_check () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#3  0xb7499b89 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#4  0xb756a7e0 in link_set_io_thread () from /usr/lib/libORBit-2.so.0
No symbol table info available.
#5  0xb74b438f in g_thread_create_full () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#6  0xb745d504 in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
No symbol table info available.
#7  0xb73f151e in clone () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.

Thread 1 (Thread -1225214288 (LWP 10156)):
#0  0xffffe410 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb746434b in __waitpid_nocancel ()
   from /lib/tls/i686/cmov/libpthread.so.0
No symbol table info available.
#2  0xb7f0d1b6 in gnome_gtk_module_info_get () from /usr/lib/libgnomeui-2.so.0
No symbol table info available.
#3  <signal handler called>
No symbol table info available.
#4  0xb7390c2b in strlen () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#5  0xb7363884 in vfprintf () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#6  0xb7381b8c in vasprintf () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.