Anomolies while Searching files in Win2k

Something has gone wrong with my file search in Windows:
When I search for the file
q996.pdf in location D:\data\projects\Production
it finds the file.
When I expand the search and look in directory
D:\data\projects
it does not find the file.
q996.pdf actually exist in a directory called:
D:\data\projects\Production\public\PRODUCTION PLANNING\Work Orders\Scanned Work Orders

Any thoughts as to why I can not find it?