Setting the default route for 44.0.0.0/8 to 44.0.0.1 plain and simple doesn't work and makes no sense. The gw sends all traffic from 44 tunnels to internet hosts to the internet via (a real, public) 44.0.0.1 address and enapsulates internet originating traffic toward a KNOWN ampr subnet via the proper tunnel. Again 44.0.0.1 is a real, routed IP address and is the gateway for all 44.0.0.0/8 traffic from the internet's point of view. No traffic is routed between tunnels at the gateway (ir is assumed that there's a ful mesh in place), and since unknown destinations have no associated tunnels, they are not routed either.
So the correct approach is to NAT the unknown 44 destinations (meaning not in the encap file or in RIP broadcasts) to your public IP and send them over regular internet. This will allow you to reach directly BGP enabled subnets, with the draw back that your traffic will seam to originate from your public IP, not your ampr address. And there's no workaround for this at the moment, unless you have a BGP announced subnet.
73s de Marius, YO2LOJ