More information is needed to investigate: exactly which documents or links are being ignored?

These URLs are listed and evaluated:
www.amelox.com/orderpage.html
www.Amelox.com/Tutor-Start.html

These URLs are not listed nor evaluated:
www.amelox.com/orderpage-ES.html
www.Amelox.com/Tutor-Start-ES.html

The difference between the two is that the content in the latter is in Spanish.
But the HTML5 in both is in English.

sorry, the computer capitalized amelox because there is a period in front.

What is the URL of the document that contains those links? http://www.amelox.com/ (the "root" page) does not contain any of those four.

(In reply to comment #4)
> What is the URL of the document that contains those links?
> http://www.amelox.com/ (the "root" page) does not contain any of those four.

Yes, the first two are in the directory. The Link-Checker finds them, too. Please look again. The server is capitalization sensitive.

These URLs are listed and evaluated:
www.amelox.com/orderpage.html
www.amelox.com/Tutor-Start.html

These URLs are not listed nor evaluated:
www.amelox.com/Orderpage-ES.html
www.amelox.com/Tutor-Start-ES.html

Thank you,
Rolf

What's needed is the URL of the document that links to the documents you mentioned. The main page does not:

$ curl -s http://www.amelox.com/ | grep -Pi '(orderpage|tutor-start)'
(produces no output)

Thank you.
I see now what is 'wrong':  Each page needs a referrer page. I fixed that even though I had not intended it at this time.

I also noted that sub-directory stand-alone pages can be checked separately.
That was not the case previously and it solves the problem. 

Thank you,
Rolf

Yes, if there are no links to a page, the link checker has no way of knowing that it exists.