I have been working with RETS and Real Estate since 2007. How are you currently getting your RETS data? From your description, it sounds like you are not seeing photos on any of the properties. If that is correct, do you know if you are hot-linking to MLS server for photos, or are you downloading and linking them from your server? I ask, because some MLS's do not permit hot linking, or it is an option that has to be enabled from their end. Please check for this if you haven't already, and let me know what you find out. If it fixes your problem, just shoot me a thanks and consider this a professional courtesy that is free of charge.
Graham
Durham, NC