Can you imagine trying to search something and Google and not being able to see what you are trying into the Google search box?
That is exactly what is happening to searchers using Apple's browser, Safari version 5.0. Of course, we are now on version 6.x, so I am not sure the number of people this is impacting but there is a large thread at Google Web Search Help with complaints.
Last night, Googler Albert responded to the thread again saying they should have a fix out for Safari 5.0 users soon but in the meantime, upgrade to the latest version of Safari to fix the issue.
Thanks again for reporting the problem. We're looking into and might have a fix out soon. In the meantime, for those who haven't been pushed a software update, you may want to download the newest version of Safari here.
Forum discussion at Google Web Search Help.