OS X :: Files Are Being Turned Into Aliases?

It started with a USB drive attached to my Airport BaseStation. It was mounted on the desktop but whenever I clicked on it I got the message:'The alias "Maxtor Basic" can't be opened because the original item can't be found.'

I have three options underneath:
1.to delete the alias - which gives me a message: 'The item "Maxtor Basic' can't be moved to the Trash because it can't be deleted.';
2.to fix the alias (this option doesn't work because if I get the network up on a Finder window all the drives show as available except the one in question, which is greyed out; and
3. to press 'OK' which basically does nothing.

I can eject the icon on the desktop but when I try and connect again I just get another icon that thinks it's an alias (there's no little arrow at the bottom of it, though). I've tried restarting the computer, disconnecting the drives and switching them off, disconnecting all users from the Airport disks page and none of these works. Is it possible the disk itself thinks it's an alias?

Following on from that I've found that some of the files in my other remote disks (attached with FireWire and USB directly to the computer) are doing the same thing. Have I caught a bug? Is this a Snow Leopard issue? Please don't tell me to format any hard drives - I've had to start again so many times recently I'm beginning to consider giving my computer away and living without it!