JS_Harris - 5:13 am on Jul 28, 2013 (gmt 0)
Seems like the spam linking is actually helping my site now...
Wordpress sites are a target of webspam in part because if you approve a comment once then you give the person making the comment permission to post future comments without being moderated so long as they don't post more than one link in future comments(default wordpress settings).
Thus they try to sneak in one real comment and come back later with their spam tools to post lots of comments on old posts, presumably to boost their 'tiered link networks' which is another fad of the moment. A fad that Matt Cutts has said will be dealt with this summer.
I also recommend you pre-approve all comments and/or change the default setting to allow no links without moderation.