RonS - 1:45 pm on Dec 9, 2010 (gmt 0)
...and now my 4th sitemap went to 0.
Maybe we can narrow down a cause?
I update all of my sitemaps 4 times a day, although only 1 generally has any changes, mostly additions.
I don't ping Google or anything.
They are extremely simple sitemaps following the format:
<?xml version="1.0" encoding="UTF-8"?>
Anyone see anything wrong or noteworthy?