There isn't currently a simple answer to this, but there is some discussion in JIRA:
Read all the comments, as there are links to other tickets that may be helpful (particularly some recent work involving the use of authority data).
If you are willing to apply some patches and/or adapt some code, you may be able to come up with a workaround.
I hope to eventually address this in an official release -- it just hasn't been a high enough priority to get done yet. If you manage to make any progress that you can share, I'm sure there are others who would appreciate the help.
From: Harris, Gary [firstname.lastname@example.org]
Sent: Friday, November 02, 2012 11:18 AM
Subject: [VuFind-General] Wrong Wiki Article
Whenever we click on a particular authorís name (Sarah Bowen), we get the wrong Wiki article. We get an article about the Australian paralympic swimmer instead of the author. There is no Wiki article for the author Sarah Bowen. We would
like to leave the Wikipedia setting on for authors, but what can we do about cases like this?