ASK [VPLS-tunnel drops]

My topology looks like that

i got R1------R2-------R3-------R4
ospf,mpls and VPLS between:
R1 and R2
R1 and R3
R1 and R4
when i disable VPLS between R1 and R2 all of them drops down.


My quastion is does anyone have similar issus?
if somone whant me to share my configuration im willing to do it