Get rid of the changes to package.inj you already made and add these instead:
In package.ini:
VirtualizeExternalOutOfProcessCOM=0
ChildProcessEnvironmentExceptions=WINWORD.EXE;EXCEL.EXE;POWERPNT.EXE;OUTLOOK.EXE;MOC.EXE
ChildProcessEnvironmentDefault=Virtual
This will make sure excel is not launched within the virtual environment of your package.