Steps to reproduce:

1/ Make sure that you have Accessibility support turned on
   for your GNOME desktop:
   Preferences->Assistive Technology Support
   then tick the checkbox at the top.
   If this is not already turned on, you will need to
   logout and log back in again.
2/ Start Orca
3/ Start gaim.
4/ (There are probably other ways to do this, but the 
    following works for me).
   Connect to an IRC server and join a channel.
5/ Type "a" in the dialog area at the bottom, then
   Insert-f
   Insert-f is a special Orca command that will speak
   the text attributes of the current character (things
   like justification and font size).

gaim terminates with the following stack trace:

t@1 (l@1) stopped in abort at 0xfd59003b
0xfd59003b: abort       :       pushl    %ebp
Current function is atk_text_attribute_get_value
 1131         g_assert (index >= 0 && index < 3);
(dbx) where
current thread: t@1
  [1] abort(0x804663c, 0x0, 0xfd933eb4, 0x9, 0xfd6326a0, 0x8045f0c), at 0xfd59003b
  [2] g_logv(0x0, 0x4, 0xfeeffcdc, 0x804635c), at 0xfd8d1238
  [3] g_log(0x0, 0x4, 0xfeeffcdc, 0xfef14b6c, 0x46b, 0xfef14b78), at 0xfd8d1265
=>[4] atk_text_attribute_get_value(attr = ATK_TEXT_ATTR_WRAP_MODE, index = 3), line 1131 in "atktext.c"
  [5] gail_misc_add_to_attr_set(attrib_set = 0x88b2cd8, attrs = 0x88d02d0, attr = ATK_TEXT_ATTR_WRAP_MODE), line 632 in "gailmisc.c"
  [6] gail_text_view_get_default_attributes(text = 0x856e150), line 724 in "gailtextview.c"
  [7] atk_text_get_default_attributes(text = 0x856e150), line 640 in "atktext.c"  [8] impl_getDefaultAttributes(0x857fb64, 0x804663c), at 0xfbfcf336
  [9] _ORBIT_skel_small_Accessibility_Text_getDefaultAttributes(0x857fb64, 0x80464d0, 0x0, 0x80464f0, 0x804663c, 0xfbfcf30c), at 0xfbfc7f52
  [10] ORBit_POAObject_invoke(0x86c5f50, 0x80464d0, 0x0, 0x80464f0, 0x8046578, 0x804663c), at 0xfbf3eb79
  [11] ORBit_OAObject_invoke(0x86c5f50, 0x80464d0, 0x0, 0x80464f0, 0x8046578, 0x804663c), at 0xfbf430a8
  [12] ORBit_small_invoke_adaptor(0x86c5f50, 0x88d01e8, 0xfbfe82d0, 0x8046578, 0x804663c), at 0xfbf3078d
  [13] ORBit_POAObject_handle_request(0x86c5f50, 0x88d0294, 0x0, 0x0, 0x0, 0x88d01e8, 0x804663c), at 0xfbf3efc0
  [14] ORBit_POAObject_invoke_incoming_request(0x86c5f50, 0x88d01e8, 0x804663c), at 0xfbf3f3d0
  [15] ORBit_POA_handle_request(0x8278880, 0x88d01e8, 0x88d0200), at 0xfbf3f865
  [16] ORBit_handle_request(0x827af08, 0x88d01e8), at 0xfbf42e70
  [17] giop_connection_handle_input(0x8640440), at 0xfbf2d97d
  [18] link_connection_io_handler(0x0, 0x1, 0x8640440), at 0xfbf491f6
  [19] link_source_dispatch(0x86bc050, 0xfbf491a0, 0x8640440), at 0xfbf4adf6
  [20] g_main_dispatch(0x8264e78), at 0xfd8c9690
  [21] g_main_context_dispatch(0x8264e78), at 0xfd8ca779
  [22] g_main_context_iterate(0x8264e78, 0x1, 0x1, 0x82488a8), at 0xfd8cab99
  [23] g_main_loop_run(0x84d9590), at 0xfd8cb19e
  [24] gtk_main(0x8046ef4, 0x8046da0, 0xfeffa840, 0xfd5e6d30, 0x0, 0x82420d4), at 0xfed113f7
  [25] main(argc = 1, argv = 0x8046de4), line 765 in "gtkmain.c"

Things of interest:

(dbx) print index
index = 3
(dbx) frame 5
Current function is gail_misc_add_to_attr_set
  632         value = g_strdup (atk_text_attribute_get_value (attr, attrs->wrap_mode));
(dbx) print *attrs
*attrs = {
    refcount           = 1U
    appearance         = {
        bg_color         = {
            pixel = 16777215U
            red   = 65535U
            green = 65535U
            blue  = 65535U
        }
        fg_color         = {
            pixel = 0
            red   = 0
            green = 0
            blue  = 0
        }
        bg_stipple       = (nil)
        fg_stipple       = (nil)
        rise             = 0
        padding1         = (nil)
        underline        = 0
        strikethrough    = 0
        draw_bg          = 0
        inside_selection = 0
        is_text          = 0
        pad1             = 0
        pad2             = 0
        pad3             = 0
        pad4             = 0
    }
    justification      = GTK_JUSTIFY_LEFT
    direction          = GTK_TEXT_DIR_LTR
    font               = 0x88ce740
    font_scale         = 1.0
    left_margin        = 2
    indent             = 0
    right_margin       = 2
    pixels_above_lines = 0
    pixels_below_lines = 5
    pixels_inside_wrap = 0
    tabs               = (nil)
    wrap_mode          = GTK_WRAP_WORD_CHAR
    language           = 0x8319060
    pg_bg_color        = (nil)
    invisible          = 0
    bg_full_height     = 0
    editable           = 1U
    realized           = 0
    pad1               = 0
    pad2               = 0
    pad3               = 0
    pad4               = 0
}
(dbx) print (int) attrs->wrap_mode
(int ) attrs->wrap_mode = 3

You'll notice that attrs->wrape_mode is 3 but there is a
specific test in atk_text_attribute_get_value() in atktext.c 
at about line 1131:

    case ATK_TEXT_ATTR_WRAP_MODE:
      g_assert (index >= 0 && index < 3);

That would appear to be a problem.