I have seen a problem develop over the course of the last two weeks with Typepad and domain mapping. I have mapped two different domains for folks, and both of them have experienced problems with the Typepad web server giving a 404 (url unknown) error. In both cases I am certain the DNS settings were done correctly.
There are at least two other users at the Typepad User Group who are having the same problem. In one of the cases I mentioned above, the problem corrected itself in a day – I suspect the correction may have resulted from a reboot of the web server or some other action on the part of the folks at SixApart.
I have submitted a help ticket with Typepad, and so far I am getting questions to make sure everything is set up correctly. I know all of the settings are correct, both in DNS and in the control panels of the weblogs in question. The fact that this problem is manifesting itself with other users indicates that it is probably a bigger problem on the Typepad side. I hope they can get it resolved quickly.
If you would like help mapping your Typepad domain, I have another post here that outlines my services in this area.