We think we've fixed the issues surrounding the new Gravatar system.
1) If the chat pages still look funny, you're probably using Internet Expolorer 6, in which case either: Hold the Ctrl key, and press F5, or: Hold the Ctrl key, and click the Refresh button.
2) If you've uploaded a Gravatar and it's not displaying, it's not a TDK issue. Either you've not uploaded the image correctly, or you've used a different e-mail address at gravatar.com to the one you use here, or Gravatar is being slow in displaying or updating your image. If the latter is the case, don't worry: it'll resolve itself sooner rather than later.