Samba and Disk spin down

[halibut]

Apologies if this has been answered before and I can't find it, or if it's because I'm still on 1.0RC2...

The samba share for my external disk keep vanishing. My Pi Model B boots fine and makes the share for the external disk available, but after a short time they disappear.

I'm assuming this is because I have configured the disk to spin down in in the xbian / xbmc menu's. Is there a way to configure Samba to leave the share up and have disk spin back up if they are accessed?

Cheers,

Hal.