Webmaster tools reporting spurious errors?

[Banknotes]

For the past 3 or so months Webmaster tools has been reporting 404 errors on my pages... The odd thing is that I can't figure out what they are seeing.

Here is an example of a link they claim is a 404

antiquebanknotes/nationalcurrency/rare/1895-Ten-Dollar-Bill.aspx

This is strange because it's a malformed URL.   It says it's linked from this page:

http://www.antiquebanknotes.com/antiquebanknotes/rare/1882-twenty-dollar-bill.aspx

Which is a URL that doesn't exist.  The bolded portion of this URRL shouldn't be there.

Can anyone give me an idea what is happening here?

Kind regards,

Greg

[Banknotes]

Hi Dana,

First, thank you for your response!  I will change my image tags and add the canonical tag.  I seem to be getting 40 to 50 of these 404's a day and my traffic and rankings have fallen dramatically.   Scary stuff.

Kind regards,

Greg

[danatanseo]

Hi Greg,

I have seen this problem rear its ugly head before and most often it was connected to the use of relative instead of absolute URLs. I notice that you are using relative URLs for images, which is very common. I also notice that there is no self-referencing canonical tag on the page.

First, I would try adding a self-referencing canonical tag to this page if possible. Then, resubmit your sitemap to GWT and wait. GWT isn't very quick, so it could take some time to see if anything changes.

Also, I would experiment with changing one page's image URLs to absolute URLs instead of relative. Again, submit to Google and wait. See if the 404 errors being reported (specifically the ones for the page you updated) go away.

How many 404 errors are there? Is it a small handful or thousands? If it's a relatively small number (in proportion to the number of overall pages on your site), I really wouldn't worry about it at all. 404s aren't bad. Google uses them all the time and they are a natural result for either a URL with a typo or content that has been removed from a site. I would suggest making a custom 404 page though, because the ones served up by default by servers are usually pretty scary and unhelpful to your end users.

Hope that helps a little. These may or may not end up being solutions, but it gives you a place to start. Cheers!

Dana