Sometimes (in most cases) OEMizers making an errors in rgu file and initflashfile.txt
My best example is 2009 google maps&GPS,I added to iolite OEM in eternlwolfs thread.
I had to install the original cab to see where those files going to,which directories created and then manually edited initflash.txt
For big applications is almost impossible to make OEM identical to its original cab.The good news is we have Rstoyguy