I found a bug which was introduced in 高速化 of 20101024.
While 20101023 doesn't have this bug.
I still don't have any idea about how to fix it currently but deleting
the following code in ONScripterLabel_animation.cpp:132 does help:
if (anim->file_name && anim->surface_name &&
strcmp(anim->file_name, anim->surface_name) == 0) return;
The example is attached in this bug report. It is stripped from the English
version of "A midsummer days resonance". It should be reproducible as
same as Japanese version because I also use nscr.exe to test it already.
* 20101118 does have this bug too.