If you're running Photoshop Elements 6, you may have had an issue where none of the effects or layer styles would appear in the Effects palette if you're running under a non-admin account.

For most users, this won't be a problem. But if you work in a corporate environment, you may not have an admin account, in which
this post over at MacOSXHints will fix your problem. Of course, you probably need admin access in order to use this tip...