I have written a trigger that calls a class, and a test class for them. When I run the test in the ide 'apex test runner' everything seems to be fine. I get 100% coverage in my class and trigger, and no warnings or errors. When I try to deploy the code to my production org I get a null pointer exception on the insert line that is highlighted below.

The trigger and class are posted below too.

Thanks!

@isTest
private class LeadHandlerTest {

    static testMethod void testLeadHandler() {
    
    List<Lead> testLeads = new List<Lead>();
    	
    	Contact contact = new Contact(NPD_Client_Satisfaction_Survey__c = 'Yes', 
							LastName = 'Test', 
							JobFunction__c =Admin', 
							Email = 'test@npd.com', 
							ContactType__c = 'NPDCustomer');
		insert contact;
    	
        Lead lead = new Lead(Phone='1234567890',
			     LeadSource='Advertising',
			     LastName='TestJohnson',
			     FirstName='Test',
			     LeadBU__c='Automotive',
			     Company='Test Company',
			     CurrencyIsoCode='USD',
			     Lead_Type__c='In-Person Meeting',
			     Status='New Leads - Not yet working',
			     Rating='Z - Not Contacted - Unknown Quality',
			     Email='test@npd.com',
			  MarketingCampaign__c = 'Web-Marketing-Opt In Web Page-200807'
							);
		testLeads.add(lead);
							
		Lead lead2 = new Lead(Phone='1234567890',
				LeadSource='Advertising',
				LastName='TestJohnson2',
				FirstName='Test2',
				LeadBU__c='Beauty',
				Company='Test Company',
				CurrencyIsoCode='CAD',
			        Lead_Type__c='In-Person Meeting',
				Status='New Leads - Not yet working',
				Rating='Z - Not Contacted - Unknown Quality',
				Email='test@npd.com'
							);
		testLeads.add(lead2);
		
		insert testLeads;
    }
}

Trigger:

trigger leadAfterInsertUpdate on Lead (after insert, after update) {
	
	if(UserInfo.getUserId() <> '00500000006z3qKAAQ'){
		
		Map<String,String> newLeadsMap = new Map<String,String>();
		
		for(Lead newLead : Trigger.new) {
			if((null != newLead.Email) && (newLead.MarketingCampaign__c == 'Web-Marketing-Opt In Web Page-200807') && (Trigger.isInsert || newLead.Email != Trigger.oldMap.get(newLead.Id).Email)) {
				if(newLeadsMap.containsKey(newLead.Email)) {
					newLead.Email.addError('Another new lead is already using this email address.');
				}else {
					newLeadsMap.put(newLead.Email, newLead.ID);
				}
			}
		}
		
		leadHandler.leadDeDuper(newLeadsMap);
	}

}

 Class

public with sharing class leadHandler {
	
    Public Static Void leadDeDuper(Map<String,String> newLeads) {
        Set<String> leadsToDelete = new Set<String>();
        Map<id,Lead> newLeadMap = new Map <ID, Lead>([Select Id, FirstName, LastName, Phone, PrimaryAreaOfInterest__c, Blog__c, Email, HasOptedOutOfEmail,Press_Releases__c,Insights_Newsletter__c,Product_Announcements__c,Marketing_Opt_Out__c from Lead Where ID IN: newLeads.values()]);
        List<Lead> leadsToDeleteList = new List<Lead>();
        List<Lead> existingLeads = new List<Lead>();
        List<Contact> contactsToDelete = new List<Contact>();
        List<Contact> existingContacts = new List<Contact>();
        
        //finds existing Leads where their email equals the incoming Lead
        for(Lead leadB : [select Id, FirstName, LastName,PrimaryAreaofInterest__c,Phone, Blog__c,Email,HasOptedOutofEmail,Product_Announcements__c, MarketingCampaign__c, Insights_Newsletter__c,Press_Releases__c from Lead where Email IN :newLeads.KeySet()]) {
            //adds the incoming lead to a set that will be deleted further down
            leadsToDelete.add(newLeads.get(leadB.email));   
                    
            //updates fields in existing leads
            leadB.HasOptedOutOfEmail = false;
            leadB.Press_Releases__c = newLeadMap.get(newLeads.get(leadB.email)).Press_Releases__c;
            leadB.Insights_Newsletter__c = newLeadMap.get(newLeads.get(leadB.email)).Insights_Newsletter__c;
            leadB.Product_Announcements__c = newLeadMap.get(newLeads.get(leadB.email)).Product_Announcements__c;
            leadB.Blog__c =newLeadMap.get(newLeads.get(leadB.email)).Blog__c;
            leadB.Marketing_Opt_Out__c = false;
            leadB.FirstName = newLeadMap.get(newLeads.get(leadB.email)).FirstName;
            leadB.LastName = newLeadMap.get(newLeads.get(leadB.email)).LastName;
            leadB.PrimaryAreaOfInterest__c = newLeadMap.get(newLeads.get(leadB.email)).PrimaryAreaOfInterest__c;
            leadB.Phone = newLeadMap.get(newLeads.get(leadB.email)).Phone;
           
            existingLeads.add(leadB);
        }
        
        if(existingLeads.size()>0) {
            update existingLeads;
        }
        //finds existing contacts where their email equals the incoming leads
        for(Contact contactA : [select ID, Name, Email, HasOptedOutofEmail, Insights_Newsletter__c, Press_Releases__c from Contact where Email IN :newLeads.keySet()]) {
            
            //adds the lead to a set to be deleted below
            leadsToDelete.add(newLeads.get(contactA.Email));
            
            //updates the existing contact          
            contactA.HasOptedOutOfEmail = false;
            contactA.Insights_Newsletter__c = newLeadMap.get(newLeads.get(contactA.email)).Insights_Newsletter__c;
            contactA.Press_Releases__c = newLeadMap.get(newLeads.get(contactA.email)).Press_Releases__c;
            contactA.Product_Announcements__c = newLeadMap.get(newLeads.get(contactA.email)).Product_Announcements__c;
            contactA.Blog__c = newLeadMap.get(newLeads.get(contactA.email)).Blog__c;
            contactA.FirstName = newLeadMap.get(newLeads.get(contactA.email)).FirstName;
            contactA.LastName = newLeadMap.get(newLeads.get(contactA.email)).LastName;
            contactA.Phone = newLeadMap.get(newLeads.get(contactA.email)).Phone;
            
            existingContacts.add(contactA);
        }
       
        if(existingContacts.size()>0) {
            update existingContacts;
        }
        
        if(leadsToDelete.size()>0) {
        	for(Lead dLead : [Select ID from Lead where ID IN:leadsToDelete]) {
        		leadsToDeleteList.add(dLead);
        	}
            delete leadsToDeleteList;
        }
        
    }

}