Cannot ping across pseudowire(L2vpn)?

Hi,

We have VC which is remote address is from ASBR(option c), Why I'm getting this "No FEC mapping" result when ping the pseudowire circuit while the VC itself is up?

I'm not able to ping the remote IP using ping MPLS feature.

ping mpls ipv4 xxxx/y source xxxx

.....

Success rate is 0 percent (0/5)

ping mpls pseudowire xxxxx 100 source xxxx

Type escape sequence to abort.

FFFFF

Success rate is 0 percent (0/5)

Trace MPLS from Source to remote VC

TRACE 1:

0 x.x.x.x MRU 9202 [Labels: 27626 Exp: 0]

L 1 x.x.x.x MRU 9180 [Labels: 24006 Exp: 0] 5 ms

L 2 x.x.x.x MRU 9202 [Labels: 57 Exp: 0] 9 ms

L 3 x.x.x.x MRU 9216 [Labels: 576580 Exp: 0] 9 ms

L 4 x.x.x.x MRU 4484 [Labels: 625970 Exp: 7] 49 ms

D 5 x.x.x.x MRU 0 [No Label] 29 ms <<<------- DS Map mismatch

TRACE 2:

0 x.x.x.x MRU 9202 [Labels: 27626 Exp: 0]

L 1 x.x.x.x MRU 9180 [Labels: 24006 Exp: 0] 2 ms

L 2 x.x.x.x MRU 9202 [Labels: 57 Exp: 0] 9 ms

L 3 x.x.x.x MRU 9216 [Labels: 576580 Exp: 0] 9 ms

L 4 x.x.x.x MRU 4484 [Labels: 625970 Exp: 7] 51 ms

L 5 x.x.x.x MRU 4484 [Labels: implicit-null Exp: 0] 54 ms

but when pinging using normal IPv4 I can reach the destination IP?

ping ipv4 xxxx source xxxx

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/37 ms

Any idea? is this because theres a break on LSP path?