HELLLLLP!!!

Why is access doing this to me. My query is not returning the few records of whatever is in the database. If I enter a salesmen's name it will return every customer name in alphabetical order but the last ones entered (ie if anything in beginning in "W" has been entered it wont return it) You can see them in the table that holds the info but a query wont call the info up. Also if you try a parameter query between 2 dates (say 03/04 and 05/04) it will return all records from 03/04 to 04/04. What is going on with the data base. It is Access 2000 with Windows 2000 as the OS so I am not sure what is going on.