i think i am experiencing something similar. As far as i can tell it has nothing to do with any kind of 'poerr-saving' features....
When i power on the computer (from being off), or reboot it, the system starts up, but the wireless is not connected/enabled...
I have to login to get it to connect.... and soemtimes THAT doesn't work, and i have to take the additional step of opening the System Preferences, and navigate to the DWA-130 Preference Pane. Once the Preference Pane opens, without needing to do anything further, it connects. This is frustrating everyone at home.
It's also a problem since this machine acts as our file sharing server, and mail server for the family. It needs to stay connected ALL the time.
What do i need to do to make this STAY CONNECTED at ALL times -- it should be enabled at boot time... and STAY connected.
Unimpressed with D-Link a little lately.