Hi, Yutaka.
I’ve tested EmEditor beta and I’ve found something unexpected in displaying Thai Language (especially Thai vowels) when using Windows 7.
It also happened in old versions of EmEditor (8.x, 9.x, 10.x) on Windows 7, too.
This behavior does not occurred in Windows XP, Windows 2003. It started to happen when using Windows Vista, Windows 7, Windows Server 2008.
Please have a look on the documents in this link.
http://www.mediafire.com/?0gyeu8uzt93ax5t
Best Regards,
Kalum K.