The problem is the rampant Serbophobia that oozes out of some influential circles in the West where everything that comes out of Serbia is treated with suspicion. Fine. See if Belgrade cares. After all, first and foremost, Belgrade's duty is the security of Serbian citizens and the BIA, DJB and others know how to deal with terrorism.
If they're not the right birds, and we waste time and resources on them?
Duh.
As soon as the Serbs start acting in an honest manner, we'll start treating them like honest partners. As things stand right now, with Serbian politicians misrepresenting everybody else's position on Kosovo to their electorate and their craven unwillingness to come to grips with Milosevic's criminal legacy as embodied by Ratko Mladic, the time for treating Serbia as an equal still hasn't arrived.
Call it Serbophobia if it makes you feel better, but it's simply a case of our treating Belgrade in a manner consistent with its behavior.