If Automatic is selected, there is a configurable timeout for the dual stack mode. This is the time that the system waits after the first of the stacks IPv4 or IPv6 has completed its configuration for the other stack to complete its own configuration. After this time has elapsed, it runs the scripts that depend on the network being up. The default timeout value is 15 seconds.
The timeout can be configured with the following parameters in System > Registry:
First ethernet device
Second ethernet device
Wireless LAN device
dual_stackto find these parameters quickly.