search of linked field not working phprunner 8

Hi
I have two tables

client (ID, name, address)

task (ID, clientID, taskref)
task table has clientID field which is linked to client table via lookup wizard

properties of this look-up are

link filed - ID from client table

display name - client name from client table

and sort type - client name from client table
the problem is on task table's list page search where i can not search by client name even though its been displayed on screen. do i need to add client name filed as well in task table? then it would be waste of database space as this information will be duplicated and will create problems when editing client name in client table.

is this something we can manipulate in settings?
BTW this is working file in phprunner 7.1 Build 21342 but not in build 22701