A Google Web Search Help thread has several reports amongst other threads and other complaints that Google Image Search is not showing the second page and beyond of images.

When you search for anything at Google Image search and scroll to the second page of results, the images are grayed out. Google has actually confirmed this bug with a specific version of Firefox, running in normal mode. When you turn Firefox to run in Safe-Mode then it works fine.

Here is a picture of what the page looks like:

We had a similar issue a year ago with Google News images.

Jay David from Google said:

Forum discussion Google Web Search Help.