bug: routes in linux kernel are not removed on withdraw if krt_metric is used

bird version: 2.0.12-7 (Debian stable) Hi, I use this config to install BGP routes into the linux kernel: protocol kernel {   kernel table 300;   scan time 10;   learn on;   graceful restart;   metric 0; # needed to override in filter   ipv6 {     import none; # kernel->bgp - nothing needed     export filter { # bgp->kernel       if ( proto = "xxx"       ) then { krt_metric = 20; accept; } # lower is choosed first by kernel       if ( proto = "yyy"       ) then { krt_metric = 30; accept; }       reject;     };   }; } This works fine. But when the route is removed (protocol gets down) it's still in the linux kernel. If I remove the krt_metric in the config it all works fine. Thanks Leif