Links in graphic header not working

I have a graphics header in http://www.irishteatowels.com with 5 links as below.

Link 2 and Link 5 do not work. They take you to
http://www.irishteatowels.com/products_new.html instead of
http://www.irishteatrowels.com/index.php?main_page=products_new

What has happened and why are the other 3 links working OK ?

Looks to me like your category links and your product links aren't working either.

This is going to be about the URL rewriting package that you're using. Those links it rewrites are failing, those that it doesn't touch are working normally.

Turn it off, and I suspect that you'll find that everything works again.

Thank you for your prompt reply. Not 100% sure what you mean. Do you mean the .htaccess file ?

All that is in it is below

RewriteEngine On
rewritecond %{http_host} ^irishteatowels.com
rewriteRule ^(.*) http://www.irishteatowels.com/$1 [R=301,L]

Have deleted the .htaccess file but still the links at top of header along with all the category links do not work. Really keen to get this sorted pronto.

http://www.irishteatowels.com/animals-and-birds-c-6.html

Your .htaccess isn't/wasn't rewriting the URLs. Something else has been added to your Zen Cart to do that as the URLs being produced are not constructed like that by Zen Cart.

There are several rewriting packages available for Zen Cart, and most likely the problem is that the one you have wasn't properly installed, and probably that the .htaccess wasn't altered to work with it.

But it's not possible to be specific without knowing which one you have.