Look, I don't want to bash you, as you clearly contributed, but in fact you made so many mistakes that it would require a very long posting to explain everything, which would be beyond scope. Please use the diff viewer as I suggested.
Every edit I performed was needed. Here are just
some mistakes you made or edits I had to perform:
- Removed images/Abstandhalter.gif (there already is a blind gif in the package that is meant to be used for that purpose)
- mixture between HTML attributes and CSS attributes is baaaad.
<table ... background="themes/beauty_of_nature/images/bg2.jpg"> is a deprecated HTML attribute. The CSS solution <table ... style="background-image: url('themes/beauty_of_nature/images/bg2.jpg');background-repeat:repeat-y;"> should be used - rolled images/index_01.jpg, images/index_02.jpg, images/index_03.jpg and images/index_04.jpg into one file (images(header.jpg). Why tile a 37 kB image? It just makes it harder for users to modify it
- Don't use <html>, but <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" dir="{LANG_DIR}"> for standards compliance
- Added the line <meta http-equiv="X-UA-Compatible" content="IE=7" /> for issues that might show up with IE8
- There's no such thing as a height attribute for the HTML tags <table> or <tr>, nor have there ever been such tags. Yet they are used on many sites, who all seem to copy one from the other. To add to the confusion, some versions of IE interpret those attributes although they never existed in the specifications of the W3C.
That's why I wrapped your table into a div container, to be able to specify a width - Use background images created by CSS instead of putting <img> tags into tables that exist for design purposes for faster loading
- HTML-Tags that don't have a closing tag (like <img>, <br>, <hr>) should use the notation <img />, <br /> and <hr /> for standards compliance without hurting older browser's rendering
- Specify border attributes for <img> tags to make sure that exotic browsers don't add borders by default.
- Some of the placeholder tokens where missing in your theme. A genuine theme for cpg1.4.x needs to contain all of those tokens
- Use proper indentation for easier edits and readability
- There was no need to define the sys and sub menu inside your theme.php. Defining the menu spacer as <br /> instead of the default :: does the trick
- Wrapping the admin menu into a table is not needed if you want it vertical
- There have been table nesting mistakes. Always validate your table