Problem populating custom tabs with custom profile fields

I'm following the article here:

https://vborg.vbsupport.ru/showthread.php?t=165554

And am getting stuck on the last bit by Wayne. Here's my plugin right now, complete with default names.

$blocklist = array_merge($blocklist, array(
	'mymodification' => array(
		'class' => 'MyModification',
		'title' => 'Gear Details',
		'hook_location' => 'profile_left_last'
	)
));

class vB_ProfileBlock_MyModification extends vB_ProfileBlock
{
	var $template_name = 'memberinfo_block_mymodification';

	function confirm_empty_wrap()
	{
		return false;
	}

	function confirm_display()
	{
		return ($this->block_data['mymodification'] != '');
	}

	function prepare_output($id = '', $options = array())
	{
   		$this->block_data['mymodification'] = 'Coming soon.';
	}
}

The "Coming Soon" at the end is just so that there's some text in the tab. What I'd like in that spot is something like:

CPF1: $post[field5]<br />
CPF2 @post [field2]<br />

Etc, etc. However as one of the posters in the article mentions, it doesn't parse the fields, it just displays the actual string. If I follow Wayne's advice on setting up the prepare_output function, the tab disappears.

Here's my plugin according to the article, which doesn't work:

$blocklist = array_merge($blocklist, array(
	'mymodification' => array(
		'class' => 'MyModification',
		'title' => 'Gear Details',
		'hook_location' => 'profile_left_last'
	)
));

class vB_ProfileBlock_MyModification extends vB_ProfileBlock
{
	var $template_name = 'memberinfo_block_mymodification';

	function confirm_empty_wrap()
	{
		return false;
	}

	function confirm_display()
	{
		return ($this->block_data['mymodification'] != '');
	}

	 function prepare_output($id = '', $options = array())
  	 {
 
        $this->block_data['custom'] = $this->profile->userinfo['field5'] : "Stuff: $this->profile->userinfo['field5']" ? "Nothing to see here";
    }}

What am I missing? If I change the last bit to the colored code above, the tab goes away. If I change it back, I'm stuck with tabs that don't parse the CPF's.

Any insight would be appreciated.

--------------- Added [DATE]1206216937[/DATE] at [TIME]1206216937[/TIME] ---------------

I got this sorted out - using the first bit of code, I ended up putting the fields in the actual template.