On a 6-core new Mac Pro (i.e., late 2013) running 10.9.2 and R2013b, parpool cannot successfully open a local pool of workers (e.g., parpool(4)). matlabpool does work, but only in a fresh MATLAB session and not if I have tried and failed to use parpool first. However, the parpool code I'm using does work on 4-core Windows 7 machines running R2013b.
Also, is this problem fixed in R2014a? I'm on a institutional license and R2014a has not yet propagated to my department.