brokaddr - 10:52 am on Jul 16, 2012 (gmt 0)

I chose a random user logged with "undefined" hits, to monitor their activity.

Interesting points:
1st visit:
Time Spent on Site: 0hrs 46mins 27 seconds
Number of Clicks: 279
Exit Page: /undefined

2nd visit:
Time Spent on Site: 0hrs 2mins 40 seconds
Number of Clicks: 40
Exit Page: /undefined

Correlation between clicks:
About 75% of the clicks were to related topics, not random as seen in typical bot activity.

To see if this were a javascript/Ajax issue, I disabled javascript for my website's domain on my own browser and browsed as a visitor would. Last page viewed was as expected (html; not "undefined")