Further to Dukes advice, check to see if there are any leading or trailing
spaces in the table, especially if the data has been imported. The TRIM
function will remove them or simply Edit > Replace 'Space' with nothing.
If the data came from a web site, they have habit of using the ASCII
character 160 which looks like a space, (ASCII32), but isn't. Use =CODE(your
cell) to check, if that returns 160 then you have them.
To remove these if they exist, highlight the whole table, use Edit >
Replace. Replace What, hold down the Alt key and type 0160 on the numeric
keypad, (nothing will appear in the box), Replace With, Nothing, Replace