Search Finder returning no results

Hi there, I'm working on a new iMac with OS Lion. When I type a search term into finder it doesn't bring up any results, even when i know there are files with that name in the folder I'm searching in. Everyone else in my company is having the same problem. It's only happening when I'm searching for files within a folder on our shared server - if I just search 'this mac' there's no problem. Any help would be greatly appreciated.