[Plugin: WordPress SEO by Yoast] Search-Page-Title can not be saved (SEO 1.1)

I did some investigating to see where things were breaking down and it appears that in the class_metabox.php file where we see this:

$content = '';
	foreach( $this->get_meta_boxes($post->post_type) as $meta_box) {
		$content .= $this->do_meta_box( $meta_box );
	}
	$this->do_tab( 'general', 'General', $content );

The $post->post_type is coming back empty. Again, this is not happening 100% of the time. It happens most of the time, but not every single time the edit page is loaded. When the issue doesn’t happen and the WordPress SEO fields are populated with its previous entry, $post-post_type is fully populated.

I’m using the latest developer version of 1.1.9, which fixed an issue I was having with selecting my Facebook Page in the social menu, but the auto-complete still doesn’t work for me. Not sure why. It works fine on a different WordPress site I have on the same host, but not on my main site. I tried disabling the two other plugins that are present on my post editing page (Yet Another Related Posts plugin, and Blubrry Podcast plugin), but the auto-complete for the keyword doesn’t work nor does the snippet preview update as I type. Anyone know what else I should check?

I’m jusing the latest version of wp (3.4.1) and the “Instinct Theme”, along with SEO Yoast version (1.2.6).

My focus keyword is not automatically populating, and it seems others have had this in the past. Where am I going wrong peeps?

All help much appreciated, as I’m new to wp, new to blogging, and new to this forum…..

Thank you,
Ian.