After upgrading to Vista, gaim 2.0.0 beta 6 no longer showed the Chinese/Japanese characters anymore in the buddy list or the chat window. To fix this, I needed to change the theme for Windows. Go to the Control Panel / Personalization / Windows Color and Appearance and click on “Open classic appearance properties for more color options” if necessary. Else, just change the fonts here. I don’t know which on you need to change. I just changed everyone from Segoe UI to Tahoma. After doing this, it seemed that things in Windows ran faster and my fonts now displayed properly!