Scenario: 2 powerbooks with airport cards. One is connected to a live DSL connection via wired ethernet. I turned on Internet Sharing on the connected book, but the internet is only partially functional on the second (over airport).

A couple of months ago this used to work fine, and as far as I know nothing has changed since then. However, I can't use email or the web anymore. FTP seems to work at 60k/s as it should. I can even ping outside servers from the remote book, but no web or mail.

WHat could possibly be going wrong?