Standard User can't add/edit custom setting record in salesforce

Question

I have created a custom settings object with two fields. I have also created a Apex controller , and a Visual Force Page to update/edit the custom settings. As a system administrator I can edit the custom settings using that form. But when I login as a standard user the form fields are not showing up. I can't add custom setting even through Setup->Develop->CustomSettings and clicking on manage, when I am logged in as standard user. I have made both my controller and Visual force page permissions to be accesible by any one.

Below is my controller code,

   public class XYZSettingsController
     {
     public  XYZSettings__c mySettings {get; set;}
     public XYZSettings__c myOrgSettings{get; set;}

     public XYZSettingsController()
        {

          mySettings = XYZSettings__c.getValues(System.Userinfo.getUserId());
          myOrgSettings = XYZSettings__c.getInstance();
            if(mySettings == null)
              {
              mySettings = new XYZSettings__c(SetupOwnerId=System.Userinfo.getUserId());
              }    

         }
    public String getOrgUrl()
    {
    return   myOrgSettings.XYZ_Url__c;
    }

    public String getOrgEmail()
    {
            return   myOrgSettings.XYZ_Email__c;
    }

    public String getUrl()
    {
            return   mySettings.XYZ_Url__c;
    }

    public String getEmail()
    {

           return   mySettings.XYZ_Email__c;
    }

    public PageReference save() {

      if(mySettings.id == null){                   
           upsert mySettings;
             }
      else{
           update mySettings;
             }
      return null;
    }
    }

And below is my Visual Force page,

<apex:page Controller="XYZSettingsController" title="Edit XYZ access settings">
  <apex:form >
    <apex:pagemessage severity="info" strength="1">
     Your default XYZ platform url is: {!OrgUrl} and Email is: {!OrgEmail}
     <br></br>
      You can override it in the settings below
    </apex:pagemessage> 
   <apex:pageBlock title="Edit XYZ settings" mode="edit">
  <apex:commandButton action="{!save}" value="Save"/>  
     <apex:pageBlockSection columns="2">  
            <apex:inputField value="{!mySettings.XYZ_Url__c}"/>
            <apex:inputField value="{!mySettings.XYZ_Email__c}"/>
    </apex:pageBlockSection>
   </apex:pageBlock>
 </apex:form>
</apex:page>

Any clues?

Answer 1

I just ran across this issue and answered it over on Salesforce. Refer to my answer there for a work around. https://salesforce.stackexchange.com/questions/28329/giving-users-access-to-a-specific-custom-setting-without-granting-them-customize/45079#45079