Quartus 7.1 Sp1 and DSPBuilder 7.1Sp1

Ok this message is the key to the problem. When PortManager.dll is loaded, it or one of the libraries it links to is misusing memory on your machine.

I suspect a library somewhere on your computer is corrupt. If you have access to Visual C++ or some other debugger, you could attach to the MATLAB process and trap the access exception which would tell us where the error was happening... Other than that I can only suggest trying another machine.