Mediatomb requires a daemon restart becuase it will not update the database (as accessed through a PS3) if a new folder is created through a samba share, this is when the directory is being watched recursively using inotify. if a file is created it is updated almost instantly.
Would be a good test to see what events inotify is giving us (if at all) when you create a directory on your mounted network drive. This could be done with inotify tools, if you feel like testing - try it (ask here if you need help to get started).
Basically, we just use inotify, we have a bug related to moving a directory, but otherwise - if inotify itself works and we get all events, then everything is fine, and if it does not, and thus does not provide the filesystem events to us, then we can't do much anyway.
Using iwatch, I can definitely see creation events. I have not been able to replicate the issue, while actively monitoring the directory and watching the inotify events…