Shared Drive and slow shutdown

I have a macbook pro running Lion(with latest update)
When I have a shared network drive mounted. it takes a really long time to shutdown.

If I eject the shared drive before shutdwon, then it shuts down really fast.
This is a pain to have to remember to eject the shared drive each time.
Is there a solution to this issue?

Not sure if this info helps:
I mount the shared drive like this: FINDER -> CONNECT TO SERVER
the server address is cifs://abc.123.com

Does the shared drive go to sleep when not used? I have three external drives that each go to sleep after a period of no use. When they're sleeping, starting applications or shutting down my MacBook Pro can take a long time. I'm still looking for a solution to get Lion to stop requiring the drives to spin up every time I do something. Anyway, it's something you might check.