I am getting the following error from one of my test scripts.

 Program_Session_Testing_New.runPositiveTestCases System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, AddSessionMembers2: execution of BeforeInsert

caused by: System.DmlException: Insert failed. First exception on row 1; first error: REQUIRED_FIELD_MISSING, Required fields are missing: [Leisure_Services_Client__c]: [Leisure_Services_Client__c]

I added the necessary Leisure Services Client data to the tables, only to have the Insert fail again, this time on row 2.  I added yet another client, only to have a failure on row 3.

Is there something obvious that I am doing wrong?  It's as if the system is trying to put in an extra record.

Here is the test script.

@isTest
private class Program_Session_Testing_New {
static testMethod void runPositiveTestCases() {
//Setup User;
//User u1 = [select id from User where alias='auser'];
//Run As U1
//System.RunAs(u1){
//List<Program_Attendance__c> addclient = new List<Program_Attendance__c>();
System.debug('Inserting user... (single record validation)');

Program__c TestProg = New Program__c (name = 'digital photos');
Insert TestProg;

Leisure_Services_Client__c TestClient = New Leisure_Services_Client__c (First_Name__c = 'Joe', Last_Name__c = 'Smith', Differentiator__c = '1', Birth_Date__c = system.today(), Postal_Code__c = 'V4V3G2');
Insert TestClient;

Leisure_Services_Client__c TestClient2 = New Leisure_Services_Client__c (First_Name__c = 'Jack', Last_Name__c = 'Smith', Differentiator__c = '1', Birth_Date__c = system.today(), Postal_Code__c = 'V4V3G2');
Insert TestClient2;


Program_Schedule__c TestSched = New Program_Schedule__c (Program__c = TestProg.id, Start_Date__c = datetime.newInstance(2009, 10, 21), Date_and_Time__c = system.now(), Normal_Credit_Hours__c = 2, Semester__c = 'Winter 2010');
Insert TestSched;

Class_Member__c classmember = new Class_Member__c(name = 'Joe Smith', Program_Schedule__c = TestSched.id, Program__c = TestProg.id, Client__c = TestClient.id);
Insert classmember;
Class_Member__c classmember2 = new Class_Member__c(name = 'Mike Smith', Program_Schedule__c = TestSched.id, Program__c = TestProg.id, Client__c = TestClient2.id);
Insert classmember2;

Program_Session__c testsession = new Program_Session__c (Program_Schedule__c = TestSched.id, Date_Time__c = datetime.newInstance(2010, 03, 01), Session_Number__c = 1, Create_Attendance_Lists__c = True);
Insert testsession;

//testsession.Credit_Hours__c = 2;

//Update testsession;


}
}

Here is the trigger that is failing.

trigger AddSessionMembers2 on Program_Session__c (Before Insert, Before Update) {

//Create list to insert into Session Attendance
List<Program_Attendance__C> ClientsforSession = New List<Program_Attendance__C>();

Set<id> ProgInstance = New Set<id>();

For (Program_Session__c PSCAC :Trigger.new){
ProgInstance.add(PSCAC.id);
ProgInstance.add(PSCAC.Program_Schedule__C);


//Check the checkboxes to see whether to proceed
If (PSCAC.Attendance_Lists_Created__c == False){
If (PSCAC.Create_Attendance_Lists__c == True) {


//Check to see if attendance is already added for the session
Double CountClientsThisSession = [Select Count() from Program_Attendance__c where Program_Session__C in :ProgInstance];
If (CountClientsThisSession == 0) {

//create a set of class members
List<Class_Member__c> AllClassMembers = New List<Class_Member__c>();
    

ID ProgSessID = PSCAC.ID;
ID ScheduleID = PSCAC.Program_Schedule__c;
String ProgSessName = PSCAC.name;

//Get the list of current attendees
List<Class_Member__c> CurrentClassMembers = New List<Class_Member__C>([Select name, Client__c from Class_Member__c where Program_Schedule__C in :ProgInstance]);

//Iterate through list
For (Class_Member__c MemberstoInsert : CurrentClassMembers){
//Check Program_Schedule_ID 

ID ClientID = MemberstoInsert.Client__c;

//build name
String ProgAttendName = ProgsessName + ' ' + MemberstoInsert.name;

ClientsforSession.add(New Program_Attendance__c(name = ProgAttendName, Leisure_Services_Client__c = ClientID, Program_Session__c = ProgSessID,Program_Schedule__c = ScheduleID));

}

}
Insert ClientsforSession;
PSCAC.Attendance_Lists_Created__c = True;
}
}
}
}