A crash occurs on a render update inside the RTSS after removing a material cloned at runtime with MaterialManager::remove("mymat").
It may not be exclusive to cloned materials, but any material created at runtime. Perhaps the RTSS isn't properly cleaning up its generated techniques. An alternate guess is it may be removing the original material rather than the clone.
Code for #0 (OgreTechnique.cpp:469):
Code for #1 (OgreShaderGenerator.cpp:1718):
Test case will follow later...
1.8 branch (September 2012)