How to solve the: "Error using comm.QPSKModulator" ?

I get this error in a fresh installed MATLAB 2012b:

Error using comm.QPSKModulator
The specified superclass 'matlab.system.SFunSystem' contains a parse error or cannot be found on MATLAB's search path, possibly shadowed by another file with the same name.

I get the same error in other functions from the Communications toolbox but not all the functions. Someone know how can I solve it?

[Wayne King]

Can you please give an example code snippet that produces this error?

[Honglei Chen]

try

rehash toolbox

and see if it resolves the issue

[NIR]

example code snippet:

qpskM = comm.QPSKModulator()

rehash toolbox - didn't work, the error is still there

[NIR]

As an extra information for this problem: it happens in 32bit and 64bit version.

[NIR]

uninstalling R2012b and installing MATLAB R2011b also didn't work Maybe it is something related to the windows path? and not Matlab path and also I tried to find reference to this:

    'matlab.system.SFunSystem'

but didn't find anything.