Some of Obi's ATA products are very similar to Linksys ATAs so following the Linksys setup (discussed near the beginning of this thread) or searching for similar issues on Linksys ATAs may provide a solution.
I first explained the issue to Obi, and they said to check with voip.ms. Voip.ms told me to check the server I was using. Kinda weird, but I could seem to get the Obi to stick with the same server setup with voip.ms. Anyway, after a bunch of retries, it stuck, and I am up and running. Blocked ONE telemarketer number....a 647 number....and already no more calls at night. Woohoo!