i must be missing something.
lets assume where searching using UserID 5.
If i run the query:
SELECT users.UserID, date_format(show_date, '%M %e, %Y') as show_date, UserFirstName, UserLastName, reserved
FROM tblbooths inner JOIN tblreserved ON tblbooths.booth_id = tblreserved.booth_id
inner JOIN users ON users.UserID = tblreserved.UserID
WHERE tblreserved.UserID != 5
GROUP BY show_date
I get the results shown in the first screen shot. this seams correct to me based on your original description. Can you explain what you you are expecting to see differently? this will help me understand what you are after.