No automatic failover when deleting contents of Unit

Hi,

We run in an failover configuration (6.0up97.8102.6335 64bit).
I had to use the "Delete content of units" from Extended tools from Console, because I wanted to change the layout of some of my raid volumes.
So I startet of to delete everthing that depended on the units on both nodes (iSCSI targets, replication tasks for log. volumes, log. volumes, volume groups) then I did the "Delete content of units" on the primary/active node.
Right after the "Delete content of unit", the virtual ip went offline, before I confirmed the reboot prompt! There was no failover and all the servers lost their volumes.
After the reboot I got the nice message "logowanie:Failover: Primary node has been started/restarted. Failover service is not running."
Funny thing: the Start button for Failover manager was greyed out, but failover not running! After hitting stop I could finally start Failover manager and end this nightmare.
Question: Is this a known bug in the software?

So now, I have to do the "delete contents of unit" on my secondary/passive node. To escape any problems, I wanted to stop the secondary/passive node in failover manager, before doing so.
So I hit stop in failover manager on secondary/passive node and was faced with this message: Deactivating this service will cause the virtual IP address to be deactivated as well. All connections to that address will be lost. Do you want to continue?

Question: Why would the virtual ip address go offline, when I stop secondary/passive node? Is there no way to do the "delete content of unit" on secondary node without loosing access to the virtual ip address??

Kind regards and thanks in advance for any help
Marco