The windows are not designed to leak... Well, they are not the kind of windows you would find on a submarine ;) You will get some water intrusion. If it is a driving rain, some can enter in gaps around the seals. The weeping holes are intended to drain off condensation that would otherwise collect on the inside of the window.
I would check to see where it is leaking from. Keep the outside caulked where the window frame meets the trailer. If the issue is a seal in the windowpane itself, you have a warranty issue on your hands. If it is where the seal where a fixed pane meets a moveable pane, and it is not too much, this may be the intended operation.
