I've experienced these bugs twice and it drove me crazy. However, I don't see same complains on the discussion board and wondering if I'm doing something wrong when performing subject line A/B testing in the email program.
What I did is to clone an old email program (had subject line A/B testing), reuse the smart list and update the email, add new A/B testing then fire it off. However, the subject line B always jumped back to the old subject line from the old email program. It didn't appear that way until the A/B testing was completed.
Have any of you ever had this experience? If so, how to avoid it? I don't really want to create an email program from scratch though. So far I've been burned twice in the past 3 weeks. I've never had this error with the A/B testing before.