Get the correct post and cat ID outside the loop

hi folks,

big problem i can’t solve alone anymore. i’m using wordpress as a cms on a language school site. to determine which sub-navigation points have to be dieplayed on the left side, i need to get the correct post and category ids outside the loop.

the site is language-school-germany.eu

in the sidebar on the left side you see the articles for the active category. the topnav links are categories. on those category pages i display just pages with the plugin category pages.

now if you go to language-school-germany.eu/en-german-courses/german-courses below you see the correct post and cat ids.

if you go to language-school-germany.eu/en-german-courses the wrong category and post id is outputed, thus also the wrong subnav is generated. cat 7 belongs to language-school-germany.eu/en-german-courses/regensburg (category), post 229 is more information about regensburg.

i can set the post 229 to draft. result: in the category above there’s another post and cat id displayed. but again the wrong one.

the code i use for the fetching and display of cat and post ids is:

global $post;
foreach((get_the_category()) as $category)$postcat= $category->cat_ID;
echo "post ".$wp_query->post->ID. " cat ".$postcat;
if($postcat)	{
	$tmp_post = $post;
	$postlist=array();
	$get_posts_args="numberposts=-1&category=".$postcat;
	$myposts = get_posts($get_posts_args);
	foreach($myposts as $post) {
		setup_postdata($post);
		$array_key=(int)get_the_ID();
		$postlist[$array_key]['permalink']=get_permalink();
		$postlist[$array_key]['title']=get_the_title();
		if(get_permalink()==($_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']))$class="class=\"act\"";
		$output.="<li><a href=\"".get_permalink()."\" ".$class.">".get_the_title()."</a></li>";
		unset ($class);
	}
	if(get_post_meta($post->ID,"reihenfolge","single"))	{
	$reihenfolge=explode(",",get_post_meta($post->ID,"reihenfolge","single"));
	foreach ($reihenfolge as $nummer)	{
		if(str_ireplace("https://","",$postlist[$nummer]['permalink'])==($_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']))$class="class=\"act\"";
		$output_sorted.="<li><a href=\"".$postlist[$nummer]['permalink']."\" ".$class.">".$postlist[$nummer]['title']."</a></li>";
		unset ($class);
	}
}

}
$post = $tmp_post;

if (!$output_sorted)echo "<ul>".$output."</ul>";
else echo "<ul>".$output_sorted."</ul>";

i just can’T find the error…