I have created a custom vf page to replace the campaign member related list.  The page has a button so users can log a call directly from the vf page for each record.  On my personal dev sandbox, the "Log a Call" button opens the task edit screen full page.  On the integration sandbox, it opens it in the page section of the page layout.  Is there some setting that is causing this?

Here is the code for my vf page:

<apex:page Standardcontroller="Campaign" extensions="CampaignMemberExtension" action="{!getData}" sidebar="false" >
    <apex:form >
        <apex:pageBlock >

          <!-- To show page level messages -->
          <apex:pageMessages ></apex:pageMessages>       
            <apex:actionFunction action="{!UpdateRecords}" name="updateRecords" rerender="pageBlock" status="status"></apex:actionFunction>           
            <apex:pageBlockTable value="{!CampaignMembers}" var="cm">
               <apex:column headerValue="Type">
                 <apex:outputText value="{!IF(cm.Contact.id = null, 'Lead', 'Contact')}"/>
               </apex:column>
               <apex:Column value="{!cm.Status}"/>
               <apex:Column headerValue="Name">
                 <apex:outputLink value="{!IF(cm.Contact.id = null,URLFOR($Action.Lead.View, cm.Lead.Id),URLFOR($Action.Contact.View, cm.Contact.id))}">
                  <apex:outputText value="{!IF(cm.Contact.id = null, cm.Lead.Name, cm.Contact.name)}"/>
                    </apex:outputLink>
               </apex:Column>
               <apex:Column headerValue="Title">
                 <apex:outputText value="{!IF(cm.Contact.id = null, cm.Lead.Title, cm.Contact.Title)}"/>
               </apex:Column>
               <apex:Column headerValue="Account">
                 <apex:outputText value="{!IF(cm.Contact.id = null, cm.Lead.Company, cm.Contact.Account.name)}"/>
               </apex:Column>
               <apex:column headerValue="Opt Out">
                    <apex:inputField value="{!cm.Opt_Out__c}"  onchange="updateRecords();" />
               </apex:column> 
               <apex:column headerValue="Attempts">
                   <apex:inputField value="{!cm.Attempts__c}"  onchange="updateRecords();" />
               </apex:column> 
               <apex:column >
                   <apex:commandButton action="{!URLFOR($Action.Activity.LogCall,null,[retURL=URLFOR($Action.Campaign.view,cm.Campaign.Id), what_id=cm.Campaign.Id,who_id=IF(cm.Contact.id = null, cm.Lead.id, cm.Contact.id)],true)}" value="Log A Call"/>
               </apex:column>   
            </apex:pageBlockTable>
        </apex:pageBlock>
    </apex:form>   
</apex:page>