deadlock engine analysis

Hey,

I was analysing a game of mine, and the engine seems a bit crazy.

I played Nd4, which the engine thinks is "good" but c5 was the best, when I tried c5, the engine states it is an inaccuracy and the best move is Nd4.

A bug?

I can't say that there isn't a problem, but stand alone engines do the same thing in some more complex positions. Part of it is a depth/horizon issue.

I guess the plan for c5 is:  c5, bxp, rc1, bd6, nxb, rxp.  I don't like giving up the two bishops, but it seemed hard to activate that bishop.  And maybe the rook on the 7th is worth something, not sure.  I don't really know what the follow-up to nd4 is.  If nd4, bg6, maybe f4 or bf3?  The first looks a little suspect at first glance, and the second doesn't seem to accomplish much.  So I dunno.