The movie I just watched has three appearances of Old Joe in the 2040 period. The first appearance (loop) he has no bag on his head and he escapes from Young Joe. The next appearance (which occurs straight after a black out shot when Young Joe first falls from the building onto the car) is when he does have a bag on his head and Young Joe shots him and recovers the gold. The third appearance/loop Old Joe comes back, once again without a bag, and he escapes for a second time.
The way I understood this was this:
Because in his first loop Old Joe escapes Young Joe and takes off with his money, Young Joe would never have been able to go to China, meet the woman and so on. So I believe the characters must have lived anoher life of thirty years and then Old Joe comes back for his second appearance/loop (as noted above), gets killed by Young Joe, so that Young Joe actually has the $$ to go to China, etc. Then, the characters live a third life of thirty years and Old Joe comes back for his third appearance/loop where he escapes for the second time.
This understanding, I think, goes a long way to indicating that the characters are in fact living multiple thirty year periods, but with a pre-determined intention each time, when their loop is meant to be closed.
The final scences where Young Joe kills himself is current day, and none of the characters Young or Old would have known of it because it is real time. Also, it is only in this current point in time when Young Joe identifies Cid as the Rainmaker, that Old Joe would also know the same fact, but by the end of that scene in real time the Old Joe trying to kill the Rainmaker no longer exists. Hence, Old Joe didn't know who the Rainmaker was until right towards the end.