On Should you secretly drill your children?, for example, I put the safety tag first and discipline second, but after submitting it reversed the tags. This isn't really that big a deal, except in some circumstances, like sharing a question, the first tag is used in the title. While discipline fits, I would consider safety the "primary" tag.
This has happened on my other questions too. Is there a way to work around it, perhaps by entering my tags in reverse order, or is there some other algorithm going on, like the most popular one being moved first?