I don't guess this is a bug, but it is strange.

I was working on a project to put on a CD with photographs for people to order from, so I wanted the filename (number) of the photo to show in the top border of the Popup box. But when I previewed the project the large version of the image would appear on a white, blank page.
It worked normally after I published it to disk.
I started trying other photographs to see if I could figure out what was causing the preview problem.
It seems it only happens with images from one Compact Flash card. I can take a shot or two with that card and put in another card and make some exposures. Only photos taken with the suspect card (Lexar 1 gig) have the problem. If there is a bug maybe it's in the card.

I noticed something similar. Some of my pop-ups open in a framed, labeled window, some on a white page as you describe. Mine come from the same SD card.

Could it be a non-standard character in the file name that is causing a problem with the popup script?

If not, if you can post an example, we might be able to spot the problem.

The filenames were left as the camera created them, like this DSC_0228.jpg, the same style was used with all cards but only the Lexar card exhibited the odd behaviour.

I did not put the project on the web as I was making a CD. But, I ended up using the Web Gallery feature in Photoshop which worked out fine for this use.

If there is problem with the card I don't have much hope that Lexar will do much about it. I bought a new card reader direct from them which lasted for 3 days and after a month I still haven't been able to get a replacement or a refund for the defective reader.

If the card was at fault, I expect that you would not be able to retrieve the image at all.

As you can, I believe the card is OK. Sigh of relief. Rather, there is some kind of weird software fault involved. Have you tried another computer?

As Harpo suggested, if you can post an example, we might be able to spot the problem.

I rechecked my sites and all pop ups open in a window now. I think it's a browser issue. Also, I had been noticing that although I size to pop up 800x600, it usually pops up smaller. For no particular reason I viewed my site "full screen", (I usually have toolbars and side panel open), and the pop ups then are full size. The browser apparently pops up a size appropriate to the size of the main viewing pane.

I was going to try Brucee's suggestion about using another computer since I still have the old one.
But I loaded one of the problem photos into Irfanview and saved it and it seems to be working okay.
It didn't matter whether I had unchecked the boxes to Save JPG comment, Save EXIF and save other things.
Maybe it removed some extra informaion that the card stores.