I have a similar problem. In particular, 2 of my drives took upwards of 30 seconds to wake up after not being used. One of these drives I've made available to the public so them having to wait 30 seconds to see a few pictures is not okay. Although my solution is nowhere near a permanent fix, it'll work until this feature is added to the Pogoplug firmware. Feel free to snub my idea, but it works for me. Here's what I did:
1. Create a publicly visible folder on the hard drive that you want to stay awake.
2. Download this file and open it up in a text editor: http://my.pogoplug.com/share/qVY4AwI8WT2HNoJdueeENg/
4. Go back over to the Pogoplug web GUI and copy/paste the url they give you for that publicly visible folder into the document you just saved.
5. Save the document again and open it up in any web browser.

Now all you have to do is open up that document when you want your drive to stay awake. I keep mine up and running all-day-every-day, but if you only want yours to be up during the day, just open the file in the morning and leave it open until you don't need it. Some people may find this annoying because you obviously need a computer on in order to make this work, but if you have a spare computer lying around, that'll work fine. You may even be able to get it to work on your Android phone or iPhone...haven't tried that yet. Hope this helps.

Although I haven't tried it, Active Copy checks periodically for new files. That may keep the hard drive awake if it checks often enough.

Might give that a try and see what happens.

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