[j-nsp] redistribute ospf into ISIS

[Plz]

  upink        uplink
      |               |
      |               |
  RouterA-----RouterB
      \              /
       \            /
        \          /
        RouterC
so ,that's is the topology.
 router A,B,C runs ospf
 router A,B, and uplink router runs ISIS

routerC 's loopback0 is redistributed into OSPF (1.1.1.1/32), so A,B,C all
have this ospf external route, default preference 150
routerA & routerB BOTH redistribute this ospf route 1.1.1.1/32 into ISIS

Here is the problem,  in my opinion,  when A & B redistribute this ospf
external route into ISIS, A&B should have this route
in both OSPF & ISIS,(A advertise this route to B via ISIS, and B advertise
this route to A in ISIS).
The fact is not this.
When i show route on A, i find 1 route in OSPF, and another in ISIS(B
advertise to A). But only the ospf route is found on B.
Seems that A didn't advertise this route 1.1.1.1/32 to B. This route (
1.1.1.1/32) was redistribute into ISIS on A coz i
find it in the A's ISIS database. Wat's more,  A didn't advertise this route
to the uplink router either.

Could anyone explain this? Any advise ll be appreciated.

Regards
runt