Sweep cache weirdness

I noticed a typo in one of my older posts and fixed it, when the cache
was
swept upon saving the updated post something strange showed up in the
production.log. I’ve truncated the results, but several articles had
multiple cache entries. Why might this happen?

Also what is the deal with '+zgi_url+.html? I’ve never written a post
titled that. Is it an artifact from a poorly written robot or something
more heinous?

Sweeping /articles/2005/10/20/’+zgi_url+.html
Sweeping /articles/2005/10/20/’+zgi_url+.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/20/myspace-ajax-exploit-explained.html
Sweeping /articles/2005/10/25/new-theme-in-progress.html