This pseudo-directory is used to access files by their ID number (aka inode number) rather than by name. For example, /.vol/234881034/105486 is file #105486 on volume #234881034.
Maybe you have some things in your /.vol directory that shouldn't normally be there. As I understand it, there shouldn't be anything actually present under that directory.
Paste the following command line into a Terminal.app window.
Code:
ls -la /.vol
If nothing happens, press the RETURN key on your keyboard.
Then drag-select the entire command output, press ⌘C to copy it to the clipboard, then paste it into a post on this thread, using CODE tags around the pasted output.