Have you tried leaving out the OemFilesPath entry? According to the documentation, this only needs to be specified if the $OEM$ folder does not exist under the i386 folder of the distribution share point, and in your case it does exist there. Also, I think you're supposed to leave out the $OEM$ part (so, if the full path is \\Server\Share\MyOEMFiles\$OEM$, you should specify the OemFilesPath as \\Server\Share\MyOEMFiles).