RSS feed not updating after initial load

Various readers loads my rss feed properly, but only on the first load. If I update that feed the reader still displays the previously fetched content (without the updates). I've checked the .xml file numerous times and it contains the most up-to-date content, the reader is just not displaying it. Any thoughts?

<cfquery name="myQuery" datasource="mySource">
SELECT * 
FROM myTable
</cfquery>

<cfset columnMapStruct = StructNew()>
<cfset columnMapStruct.content = "SUBJECT"> 
<cfset columnMapStruct.title = "SUBJECT"> 
<cfset columnMapStruct.rsslink = "URL">

<cfset meta.title = "Test Title">
<cfset meta.link = "http://mysite.com">
<cfset meta.description = "News items for my site"> 
<cfset meta.version = "rss_2.0">

<cffeed action="create" 
    query="#myQuery#" 
    properties="#meta#"
    columnMap="#columnMapStruct#" 
    xmlvar="rssXML"
    outputFile = "feed.xml"
    overwrite = "yes"
     >