[r5e]

Thanks Simon.
Checking from phpMYAdmin, a search for "vbseo" turns up turns up 4055 entries in cronlog, these are mostly records of it creating "vbseo_sitemap_task". In the datastore, there are 2 - forumcache contains what looks like linkbacks on the homepage; vbseo_options contains what looks like my license and a whole bunch of config.
There are other smatterings in some posts and PMs, but these are just where someone's typed that text, so nothing sinister. There is a table called "searchcore_text" that seems to mention the same posts where this text appears.
I have 4 tables - vbseo_blacklist, vbseo_likes, vbseo_linkback and vbseo_serviceupdate. Only the linkback table contains data, which just looks like a few old linkbacks.

Without knowing too much about what I am doing, I suspect I can delete these last 4 tables altogether. Then I only need to worry about the vbseo_options and forumcache in the datastore. As I've been warned about messing with datastore, I'm not about to wade into delete these from phpMyAdmin. What would you recommend is the best way to clean this up?

--------------- Added [DATE]1383113778[/DATE] at [TIME]1383113778[/TIME] ---------------

Originally Posted by RichieBoy67

What errors are you getting besides seeeing them in your diagnostics?

No other error, apart from the moment I globally activate plugins, I get no pages being served. I can only get my forum working with plugins deactivated (individually disabling all of them makes no difference). The only hints I can get for what might be causing this is VBSEO bits still hanging around.
I can also confirm that I've reverted all templates, but there was nothing changed there anyway.