Classic ASP, VBScript context.
A lot of articles including this Microsoft one, say you cannot use FileSystemObject to read Unicode files.
I
I am writing a windows 7 gadget and run in to the same problem, and if it is possible you can just switch your files into another encoding, for example: ANSI encoding "windows-1251". With this encoding it is working fine.
If you are using this to writing a site, then better will be to use another development approach avoiding this objects.