Not sure the best place to post bugs... but since this is Open ID related:
It seems some Yahoo! load balancers are returning 404 responses when "application/xrds+xml" is part of the "Accept" header. That is preventing OpenID libraries, such as python-openid from successful autodiscovery

telnet www.yahoo.com 80 |more
Trying 98.139.127.62...
Connected to any-fp3-real.wa1.b.yahoo.com (98.139.127.62).
Escape character is '^]'.
GET / HTTP/1.1
Accept-Encoding: identity
Host: www.yahoo.com
Connection: close
Accept: text/html; q=0.3, application/xhtml+xml; q=0.5, application/xrds+xml
User-Agent: python-openid/2.2.1 (darwin) Python-urllib/2.7

HTTP/1.1 404 Not Found
Date: Mon, 13 Feb 2012 21:20:48 GMT
P3P: policyref="http://info.yahoo.com/w3c/p3p.xml", CP="CAO DSP COR CUR ADM DEV TAI PSA PSD IVAi IVDi CONi TELo OTPi OUR DELi SAMi OTRi UNRi PUBi IND PHY ONL UNI PUR FIN COM NAV INT DEM CNT STA POL HEA PRE LOC GOV"
Cache-Control: private
Vary: Accept-Encoding
Content-Type: text/html; charset=utf-8
Age: 0
Connection: close
Server: YTS/1.20.0

Any ideas on this one? We are seeing the same issue in production too.

We would suggest you do the discovery on "https://me.yahoo.com/" instead if possible. Almost all Yahoo! users' OpenID URL areunder "https://me.yahoo.com/".Thanks,Yu WangYahoo! Membership team