Sharepoint 2010 choice field values localization

I am working on to localize lists. The lists are defined as ListInstance in Element.xml and have customschema defined in Schema.xml.

Now, to localize list column names, in Schema.xml, I am changing column's Displayname property to DisplayName="$Resources:PortalStrings,NotificationType" and it's working fine and localizing when I switch language.

On same list I have choice columns and to localize choice column's value, I am changing choice values to

<CHOICES>
          <CHOICE>$Resources:PortalStrings,ToUser</CHOICE>
          <CHOICE>$Resources:PortalStrings,ToAdmin</CHOICE>

</CHOICES>

But, its not localizing. E.g. On changing language to Spanish choice values are displaying in English only.

I have checked some out of box functionality having choice fields. And they are coded same as I am trying to do. Below is code from out of box feature,

   <Field ID="{1DAB9B48-2D1A-47b3-878C-8E84F0D211BA}"
        Name="_Status"
        Group="$Resources:Document_Columns"
        Type="Choice"
        DisplayName="$Resources:Status"
        SourceID="http://schemas.microsoft.com/sharepoint/v3/fields"
        StaticName="_Status"
        FillInChoice="TRUE">
        <CHOICES>
            <CHOICE>$Resources:core,_Status_NotStarted;</CHOICE>
            <CHOICE>$Resources:core,_Status_Draft;</CHOICE>
            <CHOICE>$Resources:core,_Status_Reviewed;</CHOICE>
            <CHOICE>$Resources:core,_Status_Scheduled;</CHOICE>
            <CHOICE>$Resources:core,_Status_Published;</CHOICE>
            <CHOICE>$Resources:core,_Status_Final;</CHOICE>
            <CHOICE>$Resources:core,_Status_Expired;</CHOICE>
        </CHOICES>
        <Default>$Resources:core,_Status_NotStarted;</Default>
    </Field>

I also tried to use out of box resource file for my choice field values but no luck.

Please let me know how to localize choice field values or anybody have faced same situation and what was the solution to make this work.

Thanks in advance.