Here's an example - "onfiction.ca".
onfiction.ca. 10800 IN A 18.104.22.168
www.onfiction.ca. 10800 IN CNAME onfiction.ca.
22.214.171.124 - 126.96.36.199
"188.8.131.52" is the third of the original Google Apps servers, replaced by the current 4 servers in November 2008. The other 2 servers in the original set of 3 have been offline for many months; and now this server joins the other 2, and is itself permanently offline.
If your custom domain uses "184.108.40.206" in its DNS addresses, your blog is probably offline too. And, that's why. You originally had 3 DNS servers providing addresses for your domain, then you had but 2, and later, only 1. This week, you have 0.
Update your DNS addresses to a righteous configuration. Or, tell your readers that you're offline.