What could this set of IDS alerts be (DDNS deaftone.com darktech.org chatnook.com, ...)?

Below is a screeny of my Squert GUI showing the Snort events. Notice they all happen at the same exact time. I cannot figure out what the source of it could be. Any ideas?

Edit: It looks like the domains are owned by DtDNS.

Edit 2: Here's another screeny with more details. It looks like its UDP protocol and port 53.