I have a basic VF page that acts as a lead submission form. After users enter the customer info, they click a "Save" button and then a "New Lead" button. 

I would like the "New Lead" button to bring the user back to the same VF page, but auto-fill in two lookup fields based on the values they entered during the first submission. 

The "New Lead" button is a custom button using a URL hack (ref: http://www.salesforceben.com/salesforce-url-hacking-tutorial/ ). The button functions correctly if I use the standard "New" record button on the object. It auto-fills the approrpriate fields as intented. However, when using it in the VF page, it brings me back to the correct VF page, but clears out the fields. 

I know the values are being passed through correctly, as they show up in the URL after clicking "New Lead." I can't figure out why they are being cleared out on the actual lead field input boxes. Am I going about this the wrong way? 

Custom Button URL (this is referenced in the VF page as New_Lead):
https://cs13.salesforce.com/a0j/e?retURL=%2Fa0j%2Fo
&CFj_id0:j_id1:j_id2:j_id5:j_id10:j_id12_lkid={!Lead_Form__c.LocationId__c}
&CFj_id0:j_id1:j_id2:j_id5:j_id7:j_id9_lkid={!Lead_Form__c.AmbassadorId__c}

Where the CFxxxxxxx values are the IDs found when using right click-inspect on the VF page for those fields
and the values after the equals sign are the two field values I am trying to pass through.

Relevant VF code below:

<apex:page StandardController="Lead_Form__c" showHeader="true" sidebar="false">
<apex:form >
<apex:pageBlock >           
 <apex:pageBlockSection title="Rep Info" columns="1" >

                  <apex:pageBlockSectionItem >
                      <apex:outputLabel value="Lookup Your Name " />
                      <apex:inputField value="{!Lead_Form__c.Ambassador__c}"/>
                  </apex:pageBlockSectionItem>

                  <apex:pageBlockSectionItem >
                      <apex:outputLabel value="Lookup Location " />
                      <apex:inputField value="{!Lead_Form__c.Location__c}"/>
                  </apex:pageBlockSectionItem>
         
</apex:pageBlockSection>    
         
                <apex:commandButton action="{!quicksave}" value="Save Lead" oncomplete="updateMessage();"  reRender="script_block" " />
                
                <apex:commandButton action="{!URLFOR($Action.Lead_Form__c.New_Lead, Id)}" id="New_Lead" value="New Lead" " />
               
</apex:pageBlock>
</apex:form>
</apex:page>