Perhaps if you post the contents of PackageContents.xml and also details of the AutoCAD/OS installation on the problem computer, someone may spot an inconsistency. Simple things you've probably already thought of:
- Problem machine actually has an AutoCAD vertical installed on it - not vanilla AutoCAD, and you've set Platform="AutoCAD"
- You set your app up as OS="Win32" and problem machine is Win64 (or vice versa).
BTW If you're using AutoCAD 2013, its better to use %programdata%\Autodesk\ApplicationPlugins, rather than %programfiles%. %programfiles% causes some problems if you want to use an MSI installer - making it hard not to install to Program Files (x86) if you run a 32-bit installer on a 64-bit OS.