I followed your instructions at https://www.jetbrains.com/help/dotmemory-unit/2.1/Working_with_Unsupported_Unit_Testing_Frameworks.html and for debug reasons I added some output in the constructor and the "Dispose" method.
With the extended methods, tests that should fail because of memory assertions have passed. It seems that the behavior depends on whether the compiler inlines the functions or not.
I thought that someone else might stumble upon the same problem and therefore I wanted to share it here. Maybe you would like to add a short information on the linked instruction page.
For clarification I uploaded some source code that shows the behavior: http://pastebin.com/xsJexD7h