Well, I tried to view one of the missing images directly and got this:
`
Warning: Illegal string offset 'current_theme' in /home/idcphotography/photography.ice-dance.com/2010-11/zp-core/functions-basic.php on line 1341
Warning: Cannot modify header information - headers already sent by (output started at /home/idcphotography/photography.ice-dance.com/2010-11/zp-core/functions-basic.php:1341) in /home/idcphotography/photography.ice-dance.com/2010-11/zp-core/i.php on line 236
Warning: Cannot modify header information - headers already sent by (output started at /home/idcphotography/photography.ice-dance.com/2010-11/zp-core/functions-basic.php:1341) in /home/idcphotography/photography.ice-dance.com/2010-11/zp-core/i.php on line 237
Warning: Cannot modify header information - headers already sent by (output started at /home/idcphotography/photography.ice-dance.com/2010-11/zp-core/functions-basic.php:1341) in /home/idcphotography/photography.ice-dance.com/2010-11/zp-core/i.php on line 238
`
And when I right-clicked, this was the URL:
`//photography.ice-dance.com/2010-11/zp-core/i.php?a=2011DallasIceGalleria&i=11DIG-201110-VM-WL.jpg&s=100&cw=&ch=&q=100&t=1&wmk=!`
When I reloaded the page, I got the images. What this tells me is that none of the images were in the cache prior to visiting the page so it's needing to create them; although, it still should have displayed a temporary image.
Could be something with the theme that you are using.
In my local test gallery, a new image has a URL like:
`//(removed)/zp-core/i.php?a=test-album&i=0022_31437_dt.jpg&s=150&cw=150&ch=150&q=75&c=1&t=1&wmk=%21&check=778ca4af5f7305c69f49b477cfa48c65732822de`
Does the issue happen if you test with a different theme? Oh wait, this is a WordPress site. What you may want to do is using the gallery directly, use something like the Cache Manager plugin (not a WordPress plug-in but one of the Zenphoto plugins) to generate all the images for your gallery so they are all in the cache. Perhaps someone with more experience integrating with WordPress can help.
Or just view every page to force the generation of the images.