Yep – the issue was the Rel value in Zenphoto Press settings. I had set this to rel=’slb_off’ to turn off the light box effect on the ZP thumbnails. For some reason each time i saved the settings my browser added another back-slash – this was causing the error. Removed the setting and things are working correctly now – thanks!
Btw – i was using the Insert Gallery feature because of the random image feature. Would be great to have the same Link options – link to Gallery, image, etc. – on the Gallery option.
Thanks again!