For some reason, when I hit the save button on my VF page, I am returned to the home page and nothing is saved.

Any ideas?

VF Page:

<apex:page standardController="Group_Call__c" id="page" cache="true" recordSetVar="unused" showHeader="True" sidebar="True" title="Log Group Call"> <apex:form id="massInsertTasks"> <apex:SectionHeader title="Log Group Call" /> <apex:pageMessages ></apex:pageMessages> <apex:pageBlock id="mainBlock" title="Group Call Details"> <!-- Holds Group Call Details --> <apex:actionRegion > <apex:pageBlockSection title="Group Call Details" columns="2" showHeader="false"> <apex:pageBlockSectionItem >Call Type <apex:inputField value="{!Group_Call__c.Call_Type__c}" /> </apex:pageBlockSectionItem> <apex:pageBlockSectionItem >Product/Drug <apex:inputField value="{!Group_Call__c.Product__c}" /> </apex:pageBlockSectionItem> <apex:pageBlockSectionItem >Call Start <apex:inputField value="{!Group_Call__c.CallStart__c}"/> </apex:pageBlockSectionItem> <apex:pageBlockSectionItem >No of People Trained <apex:inputField value="{!Group_Call__c.PeopleTrained__c}" /> </apex:pageBlockSectionItem> <apex:pageBlockSectionItem >Call End <apex:inputField value="{!Group_Call__c.CallFinish__c}"/> </apex:pageBlockSectionItem> <apex:pageBlockSectionItem >Location <apex:inputField value="{!Group_Call__c.Location__c}" /> </apex:pageBlockSectionItem> <apex:pageBlockSectionItem >Delivery Date <apex:inputField value="{!Group_Call__c.DeliveryDate__c}" /> </apex:pageBlockSectionItem> <apex:pageBlockSectionItem > <apex:outputLabel value="State/National Activity"/> <apex:outputPanel > <apex:inputField value="{!Group_Call__c.State_National_Activity__c}" required="true" /> <apex:actionSupport event="onchange" rerender="searchBlock" status="status"/> <apex:actionStatus startText="...please wait..." id="status" startStyle="color: rgb(255, 0, 0); font-weight: bold;"/> </apex:outputPanel> </apex:pageBlockSectionItem> </apex:pageBlockSection> </apex:actionRegion> <apex:pageBlockSection showHeader="false" columns="1" title="Additional Information"> <apex:pageBlockSectionItem >Additional Information <apex:inputField value="{!Group_Call__c.Additional_Information__c}" style="width: 85%;" /> </apex:pageBlockSectionItem> </apex:pageblockSection> <apex:pageBlockButtons > <apex:commandButton action="{!Save}" value="Save" /> </apex:pageBlockButtons> </apex:pageBlock> </apex:form> </apex:page>