My latest revision. I *think* I got all incidences of time-travel in Trek and I'll admit that the order of *when* these divergent time lines occur is suspect. But the "going theory" would be that the divergant timelines occured in the order we viewed them. (I.E. Archer's timeline was based off the time-travel that occured in First Contact. Since First Contact (for us) "happened first.)) But I admit that even-then it's not perfect as I was fuzzy on when certain epiosdes took place before when. And it now occurs to be that the timeline with an elder Jake Sisko would be yet another divergence but, granted, a divergence in the future, not the past. (The Visitor)
So, I'm going under the theory that every incidence of time-travel is just a shift into a parallel universe and that it's impossible to return to your "home" time you simply return to the futue of that parallel universe you entered/created.
No no no no no, the Quantum Doohicky theory states that if you jumped to the future again you could ONLY jump back to your original timeline. You could only observe the effects of the new timeline if you remained there. Hence, there are only 3 main timelines (Star Trek TOS Through Nemesis, First Contact - Enterprise and the Nero Timeline).