yahiasylhety – did you have any luck tracing this?
I’m having a similar problem. I have a multisite network:
example.com
example.com/issue001
example.com/issue002
example.com/issue003
…etc…
The parent site (example.com) returns 200 fine, but all of the subsites return 301, redirecting to themselves.
Originally one of the subsites was reported as having malware by google. I upgraded everything to latest version and the malware seems to have gone (also checked the db and used a couple of exploit scanners), but I wonder if this 301 redirect is something that got left behind?
I used the Google webmaster tools to do a “fetch as google” and I get this:
The page seems to redirect to itself. This may result in an infinite redirect loop. Please check the Help Center article about redirects.
HTTP/1.1 301 Moved Permanently
Date: Wed, 12 Sep 2012 12:19:59 GMT
Server: Apache/1.3.42 (Unix) Sun-ONE-ASP/4.0.2 Resin/2.1.13 mod_fastcgi/2.4.6 mod_log_bytes/1.2 mod_bwlimited/1.4 mod_auth_passthrough/1.8 FrontPage/5.0.2.2635 mod_ssl/2.8.31 OpenSSL/0.9.8e-fips-rhel5
X-Pingback: https://example.com/issue001/xmlrpc.php
X-Powered-By: PHP/5.3.15
Location: https://example.com/issue001/
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html; charset=UTF-8