Limited number of items in search?

Hi,

I just noticed a problem that I haven't seen before with my search box on a list page. I am finding that not all of my results are displaying in the dropdown box. Instead, it is displayed alphabetically but only goes up to 'P'. Is there a limit to the number of results displayed in a dropdown search box? If so, how do I increase the limit so that I can see the rest of the results? Thanks,

Brett