Magento creating odd URL's, no idea why. GWT reporting 404 errors

[MozAddict]

Hi Mozzes!

Problem 1

GWT and Moz, both are reporting approximately one hundred  404 errors for certain URL's. Examples shown below. We have no idea why or how these URL's are being created in Magento. Any hypothesis on the matter would be appreciated. The domain name in question is http://www.artorca.com/

These are valid URL's if /privacy is removed. The first URL is for a product, second for an artist profile and third for a CMS page

1. semi-abstract-landscape/privacy

2. jose-de-la-barra/privacy

3. seller-guide/privacy

What may be the source for these URL's?

What solution should we implement to fix existing 404's? 301 redirects should be fine?

Problem 2

Website pages seem to also be accessible with index.php in the domain name. Example Artorca.com/index.php/URL's. Will this cause a duplicate content issue? Should we implement 301's, canonicals, or just leave as is?

Cheers!

MozAddict

[Kingof5]

We run 2 sites on Magento and I've seen these problems before.

Problem 1 - this looks like a link to the privacy page (maybe in the footer?) is missing an initial /. Hence it's not being treated as relative and trying to build it onto the existing URL.

Problem 2  - shouldn't be an issue as long page has a canonical tag pointing to itself. I tried one of our pages with index.php/XXXX and it resolved and has a canonical tag pointing to it without index.php.