How do I search using Nautilus-Elementary? As soon as I click the magnifying glass, the list of files in the folder I'm trying to search disappears and tabs for SourceCode, Video and Image appear (already with some results). Changing the option that defaults to 'This week' doesn't seem to help at all either. Am I missing something seriously basic here? All I want to do is a simple search within the folder or drive I've got open in Nautilus. Any help much appreciated.
This is a known bug that affects 32-bit systems which has been fixed, you need to update.
Nautilus Elementary is no longer being actively developed: http://www.omgubuntu.co.uk/2010/11/nautilus-elementary-is-dead-marlin-file-browser/
Nautilus elementary's search now uses zeitgeist which means that you can only search the data which has been previously opened, this is the reason why you see Images, videos and source codes when you click on search because you have opened them before.
So this makes the search option in the nautilus elementary meaningless IMO.
Alternatively, you can go to Places > Search for files for a better search or you can download Gnome Tracker Tool from the software centre.