503 (Invalid Key) after a few days

Hello,

I have a page that autoloads and plays a media file. I am protecting the media file using an inline s2Member link so people cannot pass the link around and leech the file. I am using the following block of code in a PHP Code widget.

<div style="float: right;">
<?php
	$audiofile = "";
	if (is_page( 'classes-curriculum' )) {
		$audiofile = "LGJ-GSrimathi-UKS-1970-Thillana.mp3";
	}
	if (is_page( 'school' )) {
		$audiofile = "LGJ-GSrimathi-PMI-1964-Anuraagamule.mp3";
	}

	if ($audiofile != "") {
		$rkey = s2member_file_download_key($audiofile);
		$rfile = "http://www.rasika.org/wp-content/plugins/s2member-files/s2member-file-inline-yes/s2member-file-download-key-".$rkey."/".$audiofile;
		echo jwplayer_tag_callback('[jwplayer config="AudioLoop" file='.$rfile.']');
	} 

?>
</div>

This worked for the first few days. I am not sure when it stopped working, but, it has been over a month since I last observed. Now, the embedded player does not play the file. Looking at the source code, the url being generated looks correct. However, if I try to browse to just that url, I get a “503 (Invalid Key)” error.

Here is the link to the page – http://www.rasika.org/school/ and the widget is in the area right above the footer. It is set to auto-play.

I have other pages with similar s2member links – except that those are for specific member levels. Those were created just a couple of weeks back and they still work fine.

I use WP-SuperCache plugin. I cleared the cache, cleared my browser cache and cookies and tried again. I also use CloudFlare on this site. I purged the cache there as well. I viewed the source of the page before and after clearing all caches. The inline s2Member key did not change. I am not sure if this is an indicator of a problem.

Please help.

Thanks,
MediocreFred.