There have been several people requesting help using the Yahoo! Address Book web services in the .NET Developer Forum. People are getting 403 or 404 error codes back.

I did some digging into the issue this morning and the cause for the 404 error turns out to be an invalid URL for the DOCTYPE declaration for the returned XML data. In short the URL http://l.yimg.com/a/lib/pim/r/abook/xml/2/pheasant.dtd set as the DOCTYPE for the resulting successful web service call XML data is invalid.

This causes problems when using the Yahoo.Authentication class methods, such as GetAuthenticatedDataSet(), resulting in a 404 when the .NET XmlReader attempts to validate the data against the DTD.

The way to work around this issue is to use your own XmlReader with custom XmlReaderSettings specifying to ignore the DTD.

The plug got pulled on OAuth this week in several places, including Twitter and Yahoo!, with Twitter taking a lot of heat on the subject.

Yahoo! is now allowing users and developers to authorize applications, but with some additional messaging letting users know that their data may be at risk if they continue. The main idea here is obviously that developers can still continue their work while the protocol level problem is resolved.

Additional information

Yahoo!’s OAuth Update #2

OAuth acknowledgement of issue

Details on the issue from the advisory

Thanks to Engadget I'm out of another $150. They had an article about MiCasaVerde's Vera device and I just placed my order. In short it's a box that looks like a wireless router/access point (and actually works as one), but contains home automation software and support for Z-Wave (aren't I glad I've got all the switches in the house replaced with those?). Their goal is to make home automation dead simple, but for me personally (once again) the key is that it's an open platform with support for extending and hacking the device.

There's an enthusiast special going on until the end of the month (October 31, 2008) and you can get the device for $149 (plus shipping) instead of the retail $299. Details about this and the device itself are available on their wiki: http://wiki.micasaverde.com/index.php/Invitation_To_Enthusiasts

In addition to having a device that consumes 6W instead of 90+W for a PC, one other great thing I see compared to other home automation solutions is the Z-Wave adapter that comes with the device. You can unplug it from the Vera's USB port and walk around the house to register Z-Wave devices. Compare this to my experience of having to buy a handheld Z-Wave controller to walk around with, and once I was done, going into the garage, pressing a bunch of buttons on the remote (where's that manual again for the correct combination so I don't erase everything?) and running to my PC to start the transfer to the computer before the transfer times out.

Vera Pictures