In case it got buried in my other thread: If you install EMET 5.52 on a system that already has EMET 2.0 installed, your application-specific protections may not actually be enabled as the GUI may indicate. I suspect that not too many people on the planet are affected by this.
Installing 5.52 over 2.0 will not complain about the older version. And it appears to upgrade it properly. However, the default app-specific mitigations are not properly activated with the EMET shim. Until the rules are modified.