Late yesterday, the feed was completely empty - as I mentioned repeatedly. In fact, you specifically said that you had removed all Posts and were moving to using only Pages - at which point I suggested that you install an RSS Pages plugin as only posts are listed in RSS feeds by default.
Cut to 10 hours ago when I posted:
And your feed is now populated. I assume you finally installed an RSS Page plugin, yes?
Notice the reference to an RSS Page plugin? That would be because your RSS feed now contain PAGE URLs - something that is not possible without a plugin.
The feed was valid yesterday
22 hours ago your feed was empty. I even checked the feed's source file.
the feed became not valid. It then became valid again.
Feeds do not become invalid and then go valid again all by themselves. Something on the site has to change to cause, Since you're presumably the only one with access to your site...
The validity of the feed through the feed Validator is not the issue.
When you are submitting an RSS feed to a 3rd party, validity is ALWAYS an issue.
Your feed url is http://jennatalksvideo.com/?feed=rss2
This feed is currently still valid. Check it yourself and see.