There are two options that are available to you.
The first is to set the lookup to not cache data on the client. This is set on the Options Tab of the Lookup
See http://datapa.com/help/lookupwizard___lookup_options.htm for more information
The second option is to manually set the Lookups to update. There is an “Update Lookups Wizard” that allows you to force Lookups to be refreshed on the client.
The full steps involved are shown here http://datapa.com/help/update_lookups_wizard.htm