I'd like to create a bit of documentation for NAT

I've changed a bit the function and now it allows 4 different modes of terms.

Put this function in your template.php file:

(my natural language is spanish so it's possible I left some spanish comments)

/**************************************************************************
TERM PRINTING BY VOCABULARY
 $node		Node object wich we are going to use
 $vid			Vocabulary identification number
 $output_mode	'raw' = plain text
				'tag' = text+special class (to allow better formatting with css)
				'link' = link depending on the next parameter, $nat_mode
 $nat_mode		FALSE = links lead to their corresponding term (taxonomy page)
			 	TRUE = links lead to their node creator through NAT
**************************************************************************/
function phptemplate_vterms($node, $vid, $output_mode = 'raw', $nat_mode = TRUE) {
	/*global $base_url;*/
	/* We pass to $terms vector ONLY those terms wich are from our selected vocabulary */
	$tids = array();
	foreach ($node->taxonomy as $term) {
		if ($term->vid == $vid) {
			$url = taxonomy_term_path ($term);
			$terms[$term->tid] = array(
				'title' => $term->name,
				'url' => $url,
				'attributes' => array(
					'title' => $term->name,
					'rel' => 'tag'
					),
				'nat' => '');
		}
	}
/** Now we got a vector of vectors where every entry has the needed data to build a normal link leading to the taxonomy page or just a plain text output. We need to get the NID of the parent NAT node for each term (if they exist) and modify their URL to point to the parent node instead of to the term directly **/
	if ($nat_mode==TRUE) {										/* We only get the parent NIDs if we are in NAT mode (server resource saving) */
		if (is_array($terms)) {
			$tids = array_keys($terms);
			$nats = array_keys(nat_get_nids($tids));			/* This functions output [$node->id]=>$node->title, I only catch the keys */
		}
		$new_nats = array();
		foreach ($tids as $key => $tid) {
			$new_nats[$tid] = $nats[$key];						/* This way I got a more convenient format like [$tid]=>nid */
		}
		foreach ($new_nats as $key => $new_nat) {				/* Insertion of extra information (parent NIDs) in the terms vector */
				$terms[$key]['nat'] = $new_nat;
		}
	}
	$output = array();
	/* If we are NOT in link mode the plain text mode is built */
	if ($output_mode=='raw' && is_array($terms)) {
		foreach ($terms as $term) {				/* Fast method, we are not going to use the TIDs, we only need to put the variables in an array */
		array_push($output, $term['title']);	/* ... */
		}
	}
	elseif ($output_mode=='tag' && is_array($terms)) {
		foreach ($terms as $term) {														/* Again the fast method but now with extra tags for css theming */
			array_push($output, '<span class="term">' . $term['title'] . '</span>');	/* ... */
		}
	}
	/* If we are in link mode, we make the output as a link */
	elseif ($output_mode=='link'  && is_array($terms)) {
		foreach ($terms as $key => $term) {
			/*if ($nat_mode==FALSE) {}*/								/* ...if we are NOT in NAT mode, URLs are not modified */
			if ($nat_mode==TRUE) {
				$terms[$key]['url'] = 'node/' . $terms[$key]['nat']; 
			}
		}
		foreach ($terms as $key => $term) {
			$terms[$key]['url'] = drupal_get_path_alias($term['url']);	/* Making the URL with alias (in case the exist) (I got to check it also works without URL alias defined) */
			$link = l($terms[$key]['title'], $terms[$key]['url'], $terms[$key]['attributes']);
			array_push($output, $link);
		}
	}
	$output = implode(', ', $output);
	return $output;
}

And that's it, you just need to modify your theme and call to this funcion any time you need it. For example:

Link for terms of vocabulary 5 wich leads to the standard taxonomy page...

...
<tr>
    <th>Genre:</th>
    <td><?php print phptemplate_vterms($node, 5, 'link', FALSE);?></td>
</tr>
...

Link for term of vocabulary 3 that leads to the node wich created that terms through NAT...

...
<tr>
    <th>Company:</th>
    <td><?php print phptemplate_vterms($node, 3, 'link', TRUE);?></td>
</tr>
...

Regads.

PS.- I'm not a programmer so the code can be improved a lot, SURE.

Yes, simply put in your template:

print phptemplate_vterms($node, 3, 'raw', FALSE);

So, in short, you have to choose between:

• Raw text: 'raw'
• Text with extra markup: 'tag'
• Link: 'link'
• Normal link: FALSE
• NAT link: TRUE

I don't know much about this issues, but I think the problem comes from the block.

The function uses the $node variable wich -I think- is not available from blocks directly. You should "load" first the node (maybe using global or maybe with the drupal function to do it) and then you could call the function.

To check it you could try to print directly the node variable in your block with print_r($node); . If it doesn't output anything, that's the problem.

UPDATE

I think there is an error in your code:

'content' => print phptemplate_vterms($node, 2, 'raw', FALSE)

it should be

'content' => phptemplate_vterms($node, 2, 'raw', FALSE)

without "print".