We've all known for a while that leaving or arriving on the island can be a bit tricky time-wise. Apparently if you don't leave/arrive on presicley the correct bearing, there are time hiccups. I just thought maybe the bearing/angle on which you enter/leave the island affects just how big that hiccup is.
For example, the rocket from the freighter was delayed about half an hour. The doctor washed up hours early, and Ajira 316 went back from sometime in early 2008 to sometime in 2007. 815 stayed in the same year and exactley the same time but this was most likely because TPTB hadn't yet concieved of time travelling planes yet.
But what I just realized is that perhaps this applies to more than just physical things. Such as in season 1 when Sayid fixes the radio and him and Hurley both listen as it picks up some sort of 40's broadcast (granted it could be just some sort of oldies station)
And while it may be non-canon, the video from the arg where Dr. Chang's recording gets broadcasted about thirty years into the future.
Perhaps Rosseau's signal was sucessfuly sent out, but perhaps to a time before there was the proper technology for it to be picked up, or perhaps to a time that has yet to arrive.
Not that it has any major impact on the show, I just thought it was an interesting idea.