I seem to be having the same issue. I could send a screen shot via email. It seems to be when a custom application within infopath tries to programatically call another infopath window. My concern is that we have been securing our networks / computers per FDCC requirements, and that a policy may be blocking this. My suspicions are "Programatic access", "Trust Center", or "Macro Security".
On Closer inspection, The link from within info path is trying to open outlook. If outlook is open, this works. If Oulook is not open, it errors out. with the "Call was rejected by Callee"