blogspot url not working

managingnews setup working very well with wordpress blog's.
but when we try to add blogspot URL we get error

cURL error (0) Failed to connect to 2001:4860:4007:801::1005: Network is unreachable for http://xxxxx.blogspot.com/feeds/posts/default
Could not retrieve title from feed.

or error 500

HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.

we tried all possible test for adding blogspot url but its not working.

i.e.
http://xxxxx.blogspot.com/
http://xxxxx.blogspot.com/feeds/posts/default/
http://xxxxx.blogspot.com/blogspot.com/feeds/posts/default?alt=rss

anyone help us regarding this issue?