Thanks for all the previous help and here goes one that might be even simpler but I can't get it to validate.

ublic class testchangeTrigger {
  public static testMethod void test1() {
    List<Lead> leads = new List<Lead>{ new Lead(FirstName='Test 1',LastName='Test 1',Status='Open',Company='Test1',Sales_Cycle__c='Not yet contacted'),
                                       new Lead(FirstName='Test 2',LastName='Test 2',Status='Open',Company='Test2',Sales_Cycle__c='Open') };
    insert leads;
    List<task> tasks = new List<task>{ new task(WhoId=Leads[0].Id,Subject='Get Appointment',ActivityDate=System.today(), stages__c='in progress'),
                                          new task(WhoId=Leads[1].Id,Subject='Something Else',ActivityDate=System.today()) };
    insert tasks;
    Lead[] leadsgo = [select id,Sales_Cycle__c from lead where id in :leads];
    System.assertEquals('Open',Leadsgo[1].Sales_Cycle__c);
    System.assertEquals('Contacted',Leadsgo[0].Sales_cycle__c);
  }
}

 and the trigger

trigger contacted on Task (after update) {
  Set<Id> recordIds = new Set<Id>();
  List<Lead> leadsToUpdate = new List<Lead>();

  for(task t:Trigger.new)
    if(t.subject=='Get Appointment' && t.stages__C=='in progress')
      recordIds.add(t.whoid);

  leadsToUpdate = [select id from lead where sales_cycle__C = 'Not yet contacted' and id in :recordIds];

  for(Lead l:leadsToUpdate)
    L.sales_cycle__C = 'Contacted';

  update leadsToUpdate;
}

I'm not sure if this will relate,  but the trigger is (after update) and when I had pretty much the same structure to test another trigger but (before insert) it worked fine.

Thanks a lot!

B