No items found when searching sent items outlook 2003

When searching in outlook in general but especially in the sent items, it returns no items found, even if there is something recent that I can see is there it returns no items found, it hangs with the maginfer glass going in circle until you kill outlook, after closing and reopening couple of times, it works, this is happening Iterminnetly to users. Is this something on the local machine or on the exchange server, has anyone experienced  this before. Thanks for your assistance.