bt output:
(gdb) bt
#0  0x00110416 in __kernel_vsyscall ()
#1  0x00bbe2f1 in raise () from /lib/libc.so.6
#2  0x00bbfd5e in abort () from /lib/libc.so.6
#3  0x092fb289 in RNA_property_boolean_get (ptr=0xb729578, prop=0xa5a72c0)
    at /home/terry/Blender-SVN/Blender/source/blender/makesrna/intern/rna_access.c:1356
#4  0x0930132e in RNA_boolean_get (ptr=0xb729578, name=0x9a6f197 "target")
    at /home/terry/Blender-SVN/Blender/source/blender/makesrna/intern/rna_access.c:3653
#5  0x089fffd7 in snap_selection_exec (C=0xa423b68, op=0xb58b4f8)
    at /home/terry/Blender-SVN/Blender/source/blender/editors/uvedit/uvedit_ops.c:2626
#6  0x088b5e28 in wm_operator_invoke (C=0xa423b68, ot=0xa5a71a8, event=0x0, 
    properties=0xbfffee78, reports=0x0, poll_only=0)
    at /home/terry/Blender-SVN/Blender/source/blender/windowmanager/intern/wm_event_system.c:695
#7  0x088b6273 in wm_operator_call_internal (C=0xa423b68, ot=0xa5a71a8, 
    properties=0xbfffee78, reports=0x0, context=7, poll_only=0)
    at /home/terry/Blender-SVN/Blender/source/blender/windowmanager/intern/wm_event_system.c:835
#8  0x088b6436 in WM_operator_name_call (C=0xa423b68, 
    opstring=0x9a6f26d "UV_OT_snap_selection", context=7, 
---Type <return> to continue, or q <return> to quit---
    properties=0xbfffee78)
    at /home/terry/Blender-SVN/Blender/source/blender/windowmanager/intern/wm_event_system.c:884
#9  0x08a6fc91 in ui_apply_but_funcs_after (C=0xa423b68)
    at /home/terry/Blender-SVN/Blender/source/blender/editors/interface/interface_handlers.c:390
#10 0x08a7fadd in ui_handler_popup (C=0xa423b68, event=0xc6c5dc8, 
    userdata=0xae25578)
    at /home/terry/Blender-SVN/Blender/source/blender/editors/interface/interface_handlers.c:6134
#11 0x088b5133 in wm_handler_ui_call (C=0xa423b68, handler=0xa56bf20, 
    event=0xc6c5dc8, always_pass=0)
    at /home/terry/Blender-SVN/Blender/source/blender/windowmanager/intern/wm_event_system.c:357
#12 0x088b77ad in wm_handlers_do (C=0xa423b68, event=0xc6c5dc8, 
    handlers=0xa6a952c)
    at /home/terry/Blender-SVN/Blender/source/blender/windowmanager/intern/wm_event_system.c:1476
#13 0x088b82c6 in wm_event_do_handlers (C=0xa423b68)
    at /home/terry/Blender-SVN/Blender/source/blender/windowmanager/intern/wm_event_system.c:1757
#14 0x088b29cb in WM_main (C=0xa423b68)
---Type <return> to continue, or q <return> to quit---
    at /home/terry/Blender-SVN/Blender/source/blender/windowmanager/intern/wm.c:347
#15 0x088b20c7 in main (argc=1, argv=0xbffff404)
    at /home/terry/Blender-SVN/Blender/source/creator/creator.c:1294
(gdb)