[c-nsp] IPv6 weirdness

[Randy]

User complained his ipv6 gw on his vlan interface was down.  On 
checking, I couldn't ping it either from the local router.

This looked interesting to me on a sh ipv6 route for the gw IP (note 
'backup from...' line):

rtr1.ash#sh ipv6 route x:x:x:6::1
Routing entry for x:x:x:6::/64
   Known via "connected", distance 0, metric 0, type connected
   Backup from "static [1]"
   Route count is 1/1, share count 0
   Routing paths:
     directly connected via VlanXX
       Last updated 7w0d ago

After shut/no shut the interface now it's normal and pingable again:

router#sh ipv6 route x:x:x:6::1
Routing entry for x:x:x:6::1/128
   Known via "connected", distance 0, metric 0, type receive
   Route count is 1/1, share count 0
   Routing paths:
     receive via VlanXX
       Last updated 00:00:01 ago

What are the differences implying on these two outputs?

-- 
~Randy