When using Spotlight it will not index the files properly. I have "Folders" and "Images" checked; however, when I choose "Show All In Finder" and the window opens, there are other files displayed then folders and images. And I have Folders and Images dragged to the top which means they should be displayed first which they don't do once I choose Show all in Finder. This worked perfectly in previous operating systems on my other iMac. I am currently running 10.8.3.
Rebuild the Spotlight index. If you try to search now from the magnifying-glass icon in the top right corner of the display, a pulsing dot will appear in the icon. When the dot disappears, the indexing is complete.