Deja Vu analysis

Okay I just watched this film yesterday, and whilst I did enjoy it as a film, the fact that it seemed to attempt to actually make sense as a time travel story bothers me. I just didn't seem to make any sense at all. I kind of thought I might be able to see highly tenuous ways in which the sequence of events might work, but those involved fabricating multiple coexisting streams which obey different rules of time-travel... Anyway, I know there are people on here who like discussing this sort of thing, so I thought I'd start a thread :) Won't bother trying an analysis in this first post until it seems if people are interested in discussing it :)

Anyway quick summary of topic :) regardless of whether you enjoyed it, did you think the film actually made logical sense, and if so, how?