Hi Rob!
A lot isn't enough to thank you!
You have battled the same problems i did...
I've tried to disabled the PnP like you said... but was the same thing...
So, for now, i've give up to access directly to the external hdd plugged...
Then i tried to create some shortcut folders in "My Music" and "My pictures" to some folders in the external hdd in the router. What i've find out was that the Xbox 360 still can't read those folders. I tried then to add to the Media Library from WMP11 the directory from the external hdd. All the media files from the external hdd were added to the Windows Media Player Library. I thought that maybe the Xbox 360 could read the files in the WMP11 Library... because it's in the WMP11 Sharing Media that you have to configure the access from the Xbox 360. But once again i was wrong... the Xbox will not read the WMP11 Library.
My conclusion is that the Xbox 360 only read the content of the files or folders (and not shortcut folders) in the special folders like "My Music", "My Pictures", etc... both for your current user and for "All Users" directory!
What i remember today to do, and didn't tried yesterday was to customize the category of the folders in the external hdd to "Music", "Pictures", "Videos", etc... Will the Xbox only read those "special" or categorized folders??? That's what i will find out later!
Again Rob, thanks a lot!
I don't bother you more with this issue... but i will keep posting my news, problems and maybe, just maybe, some success's!!!
Best Regards,
Nuno Oliveira