Double Byte (Japanese) Page Title Becomes Obfuscated When Edited

Unicode page names look fine when first entered, but when you attempt to edit a page with a Japanese (or any non-ASCII name) the encoding gets screwed up and the name is garbled. The same problem occurs when trying to add an attachment to a page with a non-ASCII name.

To Recreate:
1. Go to the dashboard
2. Click "New Page" icon
3. Enter a non-ASCII name (example: 日本語)
4. Click "Add"
5. Click "Edit"

The page name is now garbled.