301ed Pages Still Showing as Duplicate Content in GWMT

[dfinn]

I thank anyone reading this for their consideration and time.

We are a large site with millions of URLs for our product pages.  We are also a textbook company, so by nature, our products have two separate ISBNs: a 10 digit and a 13 digit form.  Thus, every one of our books has at least two pages (10 digit and 13 digit ISBN page).  My issue is that we have established a 301 for all the 10 digit URLs so they automatically redirect to the 13 digit page.  This fix has been in place for months.  However, Google still reports that they are detecting thousands of pages with duplicate title and meta tags.  Google is referring to these page URLs that I already have 301ed to the canonical version many months ago!  Is there anything that I can do to fix this issue?  I don't understand what I am doing wrong.

Example:
http://www.bookbyte.com/product.aspx?isbn=9780321676672
http://www.bookbyte.com/product.aspx?isbn=032167667X

As you can see the 10 digit ISBN page 301s to 13 digit canonical version.  Google reports that they have detected duplicate title and meta tags between the two pages and there are thousands of these duplicate pages listed.

To add some further context:  The ISBN is just a parameter that allows us to provide content when someone searches for a product with the 10 or 13 digit ISBN.  The 13 digit version of the page is the only physical page that exists, the 10 digit is only a part of the virtual URL structure of the website.  This is why I cannot simply change the title and meta tags of the 10 digit pages because they only exist in the sense that the URL redirects to the 13 digit version.  Also, we submit a sitemap every day of all the 13 digit pages so Google knows exactly what our physical URL structure is.  I have submitted this question to GWMT forums and received no replies.

[dfinn]

It's solved then, the problem definitely lies within our code. Thanks a lot guys really appreciate your time.

[BTeubner]

http://www.internetofficer.com/seo-tool/redirect-check/ and http://www.seomastering.com/url-redirect-checker.php both say 'not search friendly'.

Kind of weird, some other tools are showing a 301. Even more weird, when i visit the url, it looks masked and i see http://www.bookbyte.com/productv3.aspx?isbn=9780321676672 (note the "productv3.aspx") which is different from what any of the tools bring back. I'm not a dev so i cant help much more. Something weird going on and i assume that's what google is seeing too.

best of luck!

[RyanKent]

Thomas,

The reason the process is not working properly is your 10 digit ISBN pages are not being redirected properly. I tried visiting your 10 digit example: http://www.bookbyte.com/product.aspx?isbn=032167667X. I am redirected to the 13 digit page, but the header code returned is 200 which means "all is ok". There should be a 301 code returned. The entire point of the 301 code is to let others (i.e. Google) know the content has moved and they should update their records. Because the 200 code is being returned, no updates are being made.

Bottom line, the redirect was not performed properly. Fix it and your issue will be resolved the next time Google crawls each page. It should take several weeks to completely resolve the issue on your site. I would recommend making the change, confirming it, then waiting 30 days and check WMT.

[dfinn]

Ricko,

Thanks a lot for the response greatly appreciated.  I just got done looking at the code, again, with the IT guys and they confirmed its a 301 redirect not a 302.  Though you are correct the URL tool that you linked to says it is a 302.  The mystery deepens.  Any other tools that you know of that I can try?

[BTeubner]

Hi Thomas,

I'm seeing a 302 redirect on http://www.bookbyte.com/product.aspx?isbn=032167667X.

Maybe try this: http://www.webtoolhub.com/tn561352-url-redirection-checker.aspx