How to resolve the following unexpected internal error in CGIR?

I get the following error while trying to compile a Simulink file

Unexpected or internal error encountered in "in CGIR: .\base_core\type\PointerType.cpp line 61: isa(aType)

Any ideas as to what could be the source of this error and how to mitigate it? I am working with R2011a version of MATLAB.

Thanks, Venkat

[Walter Roberson]

Which compiler are you using? .cpp is probably C++ code.