There are a few reasons this can happen. Each tool crawls the web at different times and see different things. I would recommend at least investigating any issues you find regardless of which tool you used to discover it.

Personally, I would pay good money for a tool from Google which used their algorithms and data, but that isn't an option so we do the best we can with the available tools. Google WMT and SEOmoz crawl reports are two parts of that solution for me.

500 errors should not happen. I would recommend determining the root issue and resolving it.

404s are a natural part of the internet. There is nothing inherently wrong with your site having some pages that offer 404 errors.

With that said, I recommend taking any pages with value that 404 and 301 them to the most appropriate page on your site. It will allow your link juice to be retained, and offer your users a better experience.

I would also recommend offering a soft 404 error page that offers a site map or other navigation help.

Thank you.

If that was my site, I would redirect your /index.html and /default.html pages to http://www.normas9000.com/.

I would then update your canonical as well. Lastly, there is no reason to have both the default and index.html pages so I would remove one of them.

You are already at a disadvantage using a hyphenated domain name. It's just another challenge using the "z" replacement.

Think about the user experience. How many people looking at your site will go to keywordguides.com when they are actually looking for keyword-guides.com? The same idea with the "z" replacement.

From a search perspective, you will not be an exact match. You will be "one off" which will put you in the same category as other mis-spelled words.

It is definitely preferable to get a .com, but if push comes to shove the options I would consider are:

• search for other TLDs such as .org, .info, .biz, etc. From a search engine standpoint, the TLD doesn't matter. Your focus would be ensuring those who look for your site are aware of your extension.

• create a brand. Twitter, Google, Myspace are all brands whose name has no indication as to the type of content is offered on their site.

• www.keyword-guidez.com is a bad option. It's bad for users who are looking for your site, it's bad for creating a keyword phrase match, and it appears a bit spammy so even when users find your results in search engines they may be less likely to click on it.

Can you share your domain name? It would make this a bit easier with specific examples.

The question I have for you is, when I type in www.yourdomain.com, what is the URL that appears in the browser? Is that URL www.yourdomain.com? or www.yourdomain.com/index.html? Also, take a look and see is you have any ReWrite's happening in your htaccess file.

In short, I recommend you 301 www.yourdomain.com/default.html to www.yourdomain.com IF you have any links (internal or external) to the default.html file. You would only make this redirect if your home page actually is www.yourdomain.com. If it is actually www.yourdomain.com/index.html then you can use that instead.

It gets confusing speaking in general terms and trying to address all the possibilities.

I would recommend friendly URLs which avoids this entire issue.

More specifically, I am suggesting your home page URL be something like www.mydomain.com, not www.mydomain.com/index.html nor www.mydomain.com/default.html

Whatever you decide, the best solution would be to 301 your old home page(s) to your new home page. You would also want to update any internal site links to your current home page. If you have control or influence to update any external links, do that as well.