late or replayed packet warning

[Jason]

I get a lot of these in my log, especially when I am moving lots of traffic
across the vpn:

Sep 20 10:45:11 titan tinc.tdvpns[16152]: Got late or replayed packet from
holden (xx.yy.zz.ww port 655), seqno 37609, last received 37610

(sequence numbers displayed generally differ by only one)

What exactly is this trying to say?  Surely this doesn't simply mean that
the udp packets arrived in a slightly different order than they were sent? 
UDP specifically doesn't guarantee that packets will arrive in the same
order.  And in practice, over the internet, packet reordering is often a
reality.

If this is the sole cause and meaning of this message, is there a way to
disable it other than commenting it out in the code?  I realize this message
can probably also warn of a replay attack, but I assume if the code can
detect this enough to log it, it can also protect itself against it?

I'm using tinc 1.0.2

Thanks
Jason