When you begin to type a directory in nautilus' address-bar (in text-mode), the directory is automatically suggested. You can press Tab then to complete it. But, when you are in the address bar and do a typo, so that it doesn't suggest, and you then press Tab, it will switch to the next "widget", i.e. the sidebar and typing into the address bar is no longer possible. This is very confusing and annoying.
Steps to reproduce:
Open nautilus and click on the text-mode button on the address bar. Now enter a Directory (like /home/user/Desk ) and it will suggest /home/user/Desktop. Press Tab to complete. But when you do a typo e.g. /home/user/Deks it wont suggest, and as a result tab will switch to the sidebar widget.
Expected behaviour:
When no suggestion is there, do nothing on "tab" when address bar text-mode is selected.
Alternate suggestion...
Instead of having the Tab button ignore the users input when it cannot complete a folder name, I would recommend that the last section of text (the one with the unmatchable folder name) be highlighted in red to alert the user to the problem.
Obviously this would need some thought so any modified theme colours do not match the warning highlight colour, but there you go....