Looking for a Bryce Guru answer here. I created some models in obj format and then imported into Bryce 4 & 5 and saved as obp format. They have worked fine on our Macs and the Macs of others. I recently sent some to a PC user via CD in ISO format and they (models) will not open. Sent them again via email with same results. Is there something special I have to do to make the files compatible with PC versions of Bryce?