Sequence lock

Hey all,
I trying to run 2 sequeces (seq_a; seq_b) on 2 sequencers (seqr_a; seqr_b) and I want seq_a to lock the virtual sequncer. in other words seq_b would be blocked until seq_a unlocks the virtual sequencer.
this will help me not killing a functional sequence when reset is activated.But i get the error : " virtual sequencer should not finish before locks from itself and desscent sequences are removed. the lock held by the child sequence is being removed "
Any thoughts that could help me ?