I too am experiencing the same problem and i've been wrestling with it for a couple of weeks now. I am running a x64 Vista ultimate system and VMCNetflix used to work fine. In fact it was awesome and rarely had any issues. Once i upgraded, it stopped working. Problem is that regardless of whether i try to go back to the earlier good version, it still doesnt work. I have tried 1.1.4x64 also with no luck, i saw that the 1.1.4R2x64 had been deprecated.
After reading through the blog, i tried doing a search for the ExtenderSetupLib, ExtenderSetupLib.dll, and VMCExtenderSetupLib.dll without any luck. The search includes non-indexed files, hidden files, and system files. I am guessing that i need to delete this file, wherever it may be. I've uninstalled, reinstalled, etc...
...but on my Xbox i still get that i'm running an invalid application on the Xbox and it closes out of the VMCNetflix program to plain ole media center. Any help would be appreciated, i have no idea what to do next and my girlfriend is bugging me about her Law and Order. I need a quick resolution. :)
Alex