similar issue
Sorry to bump up an old thread, Just didn't think this was worth starting a new one.
I'm currently having a very similar problem, I have somehow changed the permissions on an external firewire HD and it won't show up in finder anymore. I have tried doing what people have suggested here, however no matter what I do I can't delete the Alias.
If i disconnect the hard drive, it doesn't appear in the /volumes folder allowing me to delete the alias, and if i leave it connected I'm told I don't have permission to delete the alias. I've tried restarting and all.
Can anyone help? I would be so grateful as the hard drive has all my uni coursework on it!
Andy