How can I get Chinese/Japanese characters to display properly instead of squares?

Okay fine.... I stopped being lazy and found the solution by trial and error. So the trick is to change the system locale to Chinese (PRC) and then changing the system locale back to English (United States). I can now see the Simplified Chinese characters correctly in my buddyllist as well as in browser titles. I've attached a screenshot of the menus to get to the system locale. Basically go where you changed your input method and follow the screenshot below:

http://www.twitpic.com/18uhgc

This is a bug with the IME, I think, but nothing a few changes and reboots won't fix! Good luck!

You have hit the nail on the head.

 just followed your instructions and not the languages display correctly.

I changed the locale twice, once to Japanese(Since Japanese is what I wanted to see) and then to Chinese and finally back to English.

Now all the files display like a charm.

I've noticed the same behavior. However, I am almost certain that it applies only to the Simplified Chinese character set. I've tried to go to google.com.hk and search with Traditional Chinese. The title shows the traditional characters just fine. However, when I go to google.cn and search in Simplified Chinese, I can see that the simplified characters are updated in the title as blocks. So I believe that the song titles or whatever you have that show up as blocks are simplified characters. Someone please verify this for me? So I think an update to the character set, maybe, could fix it? Microsoft? Ball is in your court! ;)

That's exactly my problem too. It'st not just limited to 64 bit too. It happens on my other laptop which is 32bit Ultimate.

For example, the page tabs in Google Chrome's browser simply display squares, so when I'm using Chinese websites, I can't navigate as easily...  And I can't save any of my files or media information in Chinese or Japanese.