This bug is still there with newest scim-uim (0.1.4).

GDB backtrace:
#0  0xb725b5b1 in gc_mark (ptr=0x639) at slib.c:2736
#1  0xb725b5d2 in gc_mark (ptr=0x81f49d8) at slib.c:2740
#2  0xb725b604 in gc_mark (ptr=0x81fe488) at slib.c:2747
#3  0xb725b5d2 in gc_mark (ptr=0x81fe4e8) at slib.c:2740
#4  0xb725b604 in gc_mark (ptr=0x81a4940) at slib.c:2747
#5  0xb725b604 in gc_mark (ptr=0x81a2290) at slib.c:2747
#6  0xb725b6b5 in mark_locations_array (x=0xb726e220, n=39) at slib.c:2784
#7  0xb725b709 in mark_locations (start=0xb726e220, end=0xb726e2bc)
    at slib.c:2800
#8  0xb725babc in gc_mark_and_sweep () at slib.c:2922
#9  0xb725bb53 in gc_for_newcell () at slib.c:2944
#10 0xb7258dad in cons (x=0x81fe528, y=0x0) at slib.c:1673
#11 0xb725c9e5 in leval (x=0x81fe528, env=0x81a2290) at slib.c:3268
#12 0xb725ce71 in lapply (fcn=0x81feb48, args=0x81a4950) at slib.c:3334
#13 0xb7260550 in funcall1 (fcn=0x81feb48, a1=0x81a56b0) at slib.c:4750
#14 0xb725f84d in mapcar1 (fcn=0x81feb48, in=0x81a5030) at slib.c:4449
#15 0xb725fc13 in mapcar (l=0x81a4a50) at slib.c:4496
#16 0xb725cdd3 in lapply (fcn=0x81a3230, args=0x81a4a50) at slib.c:3324
#17 0xb725c293 in leval (x=0x81afe80, env=0x81a4990) at slib.c:3151
#18 0xb725beaf in leval_args (l=0x81a4aa0, env=0x81a4c50) at slib.c:3051
#19 0xb725d876 in leval_let (pform=0xbf8c6200, penv=0xbf8c6204) at slib.c:3579
#20 0xb725c661 in leval (x=0x81a4e60, env=0x81a4c50) at slib.c:3201
#21 0xb725d4ba in leval_progn (pform=0xbf8c62e0, penv=0xbf8c62e4)
    at slib.c:3469
#22 0xb725c661 in leval (x=0x8200a68, env=0x81a4f30) at slib.c:3201
#23 0xb725d4ba in leval_progn (pform=0xbf8c63c0, penv=0xbf8c63c4)
    at slib.c:3469
#24 0xb725c661 in leval (x=0x81a6e70, env=0x81a6d80) at slib.c:3201
#25 0xb7256c91 in repl (h=0xbf8c6460) at slib.c:650
#26 0xb725755b in repl_driver (want_init=0, h=0xbf8c6460) at slib.c:899
#27 0xb7258933 in repl_c_string (str=0x8388838 "(create-context 0 '#f '#f)",
    want_init=0, want_print=0) at slib.c:1504
#28 0xb7263007 in uim_scm_eval_c_string (
    str=0x8388838 "(create-context 0 '#f '#f)") at uim-scm.c:308
#29 0xb72651f9 in uim_eval_string (uc=0x8387f28,
    buf=0x8388838 "(create-context 0 '#f '#f)") at uim-func.c:331
#30 0xb7254b33 in uim_create_context (ptr=0x0, enc=0xb727c06f "UTF-8",
    lang=0xb72688f2 "#f", engine=0xb72688f2 "#f", conv=0xb726d110, commit_cb=0)
    at uim.c:192
#31 0xb7275922 in uim_LTX_scim_imengine_module_init ()
   from /usr/lib/scim-1.0/1.4.0/IMEngine/uim.so
#32 0xb7f0c287 in scim::IMEngineModule::load (this=0xbf8c66cc,
    name=@0x819b0f8, config=@0x8058378) at scim_imengine_module.cpp:69
#33 0xb7296428 in get_factory_list (config=@0x8058378, uuids=@0xbf8c6818,
    names=@0xbf8c680c, langs=@0xbf8c6800, icons=@0xbf8c67f4)
    at scim_imengine_setup.cpp:636
#34 0xb72994ea in load_factory_list (config=@0x8058378)
    at scim_imengine_setup.cpp:680
#35 0xb7299a1a in load_config (config=@0x8058378)
    at scim_imengine_setup.cpp:1026
#36 0xb7299bda in aaa_imengine_setup_LTX_scim_setup_module_load_config (
    config=@0x8058378) at scim_imengine_setup.cpp:98
#37 0xb7a106cf in SetupModule::load_config (this=0x8180580, config=@0x8058378)
    at scim_setup_module.cpp:132
#38 0xb7a0e7b5 in SetupUI::add_module (this=0x8058350, module=0x8180580)
    at scim_setup_ui.cpp:126
#39 0xb7a10b3f in setup_LTX_scim_helper_module_run_helper (uuid=@0xbf8c6b54,
    config=@0xbf8c6b34, display=@0xbf8c6b5c) at scim_setup_helper.cpp:96
#40 0xb7f00f3c in scim::HelperModule::run_helper (this=0xbf8c6b44,
    uuid=@0xbf8c6b54, config=@0xbf8c6b34, display=@0xbf8c6b5c)
    at scim_helper_module.cpp:123
#41 0x0804bae9 in main (argc=3, argv=0xbf8c6c84)
    at scim_helper_launcher.cpp:169