Thanks for the answer, it was really detailed.
You were right, the Property Photo had type URL, I removed that and I got the Image.jpg but only URL, not the image... now that you gave me that hint of using the type String it worked fine, anyway, I will also look for the thread in the mailing list which talks about the Type:Image.
If you want to know what I was doing before to realise about that problem.... when I updated the SMW, I got a lot of warning messages, then after I run the maintenance scripts and most of the warning messages dissappeared, but no those refeared to the images and the "Empty Strings".
Thanks, I'll try now to read about the new issues in this SMW 1.0-RC3
Carlos Eduardo Atencio Torres