[j-nsp] iBGP and IPv6

[Jonathan Call]

So I have a lab with two routers exchanging iBGP between them. They have both IPv4 and IPv6 addresses configured on the loopback. There aren't any export or import policies defined between the two. When I examine the routes for the local loopback interface on router1 I see the following:
router1> show route 172.30.110.248
vr-1.inet.0: 15 destinations, 24 routes (15 active, 0 holddown, 2 hidden)+ = Active Route, - = Last Active, * = Both
172.30.110.248/32    *[Direct/0] 6d 19:54:25                    > via lo0.1                    [OSPF/10] 6d 19:54:20, metric 0                    > via lo0.1
router1> show route 172.30.110.248 hidden
vr-1.inet.0: 15 destinations, 24 routes (15 active, 0 holddown, 2 hidden)+ = Active Route, - = Last Active, * = Both
172.30.110.248/32     [BGP ] 21:19:38, from 172.30.110.249                      AS path: I                      Unusable
This seems to be as expected. This is the IPv6 loopback route information:
 router1> show route 2001:db8:4000::1
vr-1.inet6.0: 9 destinations, 13 routes (9 active, 0 holddown, 0 hidden)+ = Active Route, - = Last Active, * = Both
2001:db8:4000::1/128*[Direct/0] 6d 20:02:07                    > via lo0.1                    [OSPF3/10] 6d 20:02:02, metric 0                    > via lo0.1                    [BGP/170] 00:21:37, MED 1, localpref 100, from 2001:db8:4000::2                      AS path: I                    > to fe80:db8:4000:1::3 via ge-0/0/8.0
Why does the router flag the BGP route for the IPv4 loopback as Unusable but doesn't do the same for the IPv6 loopback address? Does it even matter?
Jonathan