(UPDATE 8 July 2016: See this post for some information and links regarding a debate brought about by this paper.)
My paper 'Two New Counterexamples to the Truth-Tracking Theory of Knowledge' is forthcoming in Logos & Episteme. It derives from this blog post. The final draft is available at PhilPapers.
An interesting point about its origin: I was originally playing with what I thought might be a type of counterexample to the truth-tracking account involving weird self-referential propositions. After investigating for a stretch I concluded that the approach was no good, at which point the counterexamples in the present paper (which have nothing to do with self-reference) came into my head. Something about the disappointment at the weird self-referential approach failing, together with the fact that I had during the investigation started to get used to the idea that I was able to refute the truth-tracking theory, caused me to think of the actual counterexamples.
For another recent counterexample to the truth-tracking theory (which also works against some other theories) see Neil Sinhababu and John Williams's paper 'The Backward Clock, Truth-Tracking and Safety' and Sinhababu's blog post about it.