Upon executing a task before insert trigger, I am trying to update an activity custom field  "Assigned_Region__c" by concatenating two text field values derived from the user.
Looking @ the code below, when I create a task, then look @ the debug logs, strConcatenate appears concatenated correctly- I get the values I'm expecting.  However, on the next line of code, when I try to  assign strConcatenate value to the Assigned_Region__c field (Type:  Text Area(255)), nothing happens - the field never populates with the value from strConcatenate once the record is inserted, nor do I get any errors.  I have checked that the field level security is set to be visible to all profiles including mine.  Any thoughts as to the cause?  Thanks in advance for your help - Bronco.

CODE:

trigger UpdateAssigned on Task (before insert) {
    String tskAssigned;
    for (Task tt : Trigger.new)
    {      
     tskAssigned = tt.Owner.Id;
        String uProf =  [SELECT Profile.Name FROM User WHERE id =: tskAssigned LIMIT 1].Profile.Name;//uProf stores user Profile Name
        String uRegion =  [SELECT Region__c FROM User WHERE id =: tskAssigned LIMIT 1].Region__c;//uRegion stores user Region 
        String strConcatenate = uProf + ' ' + uRegion;
        system.debug('strConcatenate= ' + strConcatenate);//debug log shows "SADMIN East" which is what I expect
        tt.Assigned_Region__c = strConcatenate;
    }
}