<title>[[+seoPro.title:default=`[[*pagetitle]]</title>
I've never used seoPro, but I would guess that the seoPro plugin (if activated) will set both of those placeholders for you.
<title>[[*pagetitle]]</title>
<title>[[++site_name]] | [[*pagetitle]]</title>
Could it be a TV?
Are any of the titles it uses different from the pagetitle? If not, you could just change the tag to this:
<title>[[*pagetitle]]</title>
or what I often use:
<title>[[++site_name]] | [[*pagetitle]]</title>
It might be a property of the plugin. If you edit the plugin, you might see the name of a property set. If so, you could edit it in System -> Property Sets.