1.3 and strict NAT?

Hi,
I've been using m0n0wall for several years now. Most recently I was on
1.2(something). My two lads who both use XBOX 360 reported that NAT
was showing
as 'moderate' from their xboxes. This usually does not cause a problem.

However recently I upgraded to m0n0wall 1.3 and now NAT shows as strict?

I can't see any changes in the config that may have caused this to happen.
I realise that m0n0 does not support upnp for good reason but if I
could get things working
back as how it was, ie moderate nat, then I would be happy.

Many thanks

Mike