As a non expert in any of this. and going on just gut feeling.  Perhaps the FDA is just being for the lack of a better word "difficult".  I guess they just want to make sure things are on the up and up,  Before graduating them to human trials.

Perhaps its one more or a couple of more animal experiments that would clarify a few things that may have been overlooked.  I'm sure its something either doctors could handle quickly and efficiently.  I'm sure its not difficult to get a couple of guinea pigs or mice or whatever animal they need to do a couple of more experiments.  

And I'm sure the new person they just hired will contribute some of his expertise.  Dont really know.  Just going off the top of my head.

I dont know, I'm just not that worried, they weren't rejected or anything.  And the fact that they are conversing back and forth seems to be very encouraging.  Take it for what its worth.

A flat out denial I think is the time to show a little bit of concern.  Other than that it just seems like everything on path.  Just keep buying cheapies when you can until the big announcement.