lots of security advisories rehashed

[Graham Menhennitt]

I subscribe to the RSS feed of FreeBSD security advisories 
(http://vuxml.freebsd.org/freebsd/rss.xml). Today, it told me that there 
were forty-something advisories. I went to the VuXML site and saw that a 
stack of old entries have been updated to have today as their "Entry" 
date. What's the reason? Is it something to be worried about?

Thanks,

     Graham