I have an iMac which has an external USB hard drive connected to it. I also have a Macbook Pro which I connect to the network via AirPort Express. Both computers use Mac OS X 10.6.4

When I connect to the Network on the MBP the external HD only shows up if someone is logged in on the iMac. Also, the MBP's connection to the HD breaks if they log out.

I used to have no problem accessing the HD whether not not someone was logged in. Now, it doesn't work anymore. I don't know how to get it to show up if no one on the iMac is logged in.