Glenn
I've had this problem lately (2-3 weeks) with photos/images on other sites. Have not had problem here on A-Data.
I usually clear the browser cache, and restart browser.
This fixes the problem, for me.
Problem usually starts when the firefox cache gets large (approx 750 MB-1 GB), after a lot of web-cruising.
Currently using Windows 7x64, Firefox 17.0.1, and several firefox plug-ins running. Java 17 also on my system.
See if this works: right-click on your half image and choose view image from drop-down menu.
John