Hi,
creating a sub-VI with the "Create from Selection" button from the ribbon may have a devastating effect on the routing in the diagram:
Before:

After:

Also, in general, the option to turn off auto-routing in the preferences seems to have no effect. Wires keep getting re-arranged once in a while.
In general, it would be desirable to be able to lock the position of selected VIs and wires.
LVC version 1.0.0.50009
Nicola