So, there is the problem in "my procedure".

http://kb.open-e.com/entry/147/
When running Volume Replication the destination volumes are not available while they are selected as destination volume.

Before stoping Volume Replication tasks, only paths of source Volumes are active(I/O) and VM hosts can't use (manually entereed) paths to destination Volumes.
I suppose, I'm not fast enought to make switchig procedure and reconnect paths between nodes.

Idea Nr. n+1:
After Manual Failover, Secondary DSS is active. Paths using Virtual IPs are still active (I/O). Can we add paths using Physical addresses of Secondary Node, now?