A confirmed bug with the Google Custom Search Engine is being discussed at the Google Custom Search Help forum.
The bug appears when doing a search for a set promotion using a Google Custom Search Engine interface. What happens is the search results appear halfway down the page below the advertisements on the right.
This only occurs in Google Chrome, Google's browser.
Google said they are aware of the issue and they are working on a fix. Googler Prathap Reddy said:
We are aware of the issue. We are working on identifying a fix for this issue.
Forum discussion at Google Custom Search Help.