Most of the time, yes. It can work (Back to the Future, Futurama, the new Star Trek come to mind). But it can also be a colossal train wreck (Heroes springs to mind).Time travel plots are convoluted, ridiculous, and an easy out for bad writers.
I will still see this movie, against my better judgement.
I'll add an addendum to my comment: If the series plot focuses/involves time travel from Day 1, it's not held to the previous standards. Generally speaking, time travel only works well if it's there at the beginning. That's why BttF and Futurama made it work.Most of the time, yes. It can work (Back to the Future, Futurama, the new Star Trek come to mind). But it can also be a colossal train wreck (Heroes springs to mind).