If you would prefer a non-code approach, you could try and use,
<Edit> <Replace>
*AFTER* first identifying the actual character that is appended to your
data.
With a "bad" number in A1, enter this in B1:
=Code(Right(A1))
This should give you the Char() value of the "space",
Which is probably Char(160), as David mentioned.
Knowing this Char() value, select all the cells containing these "bad"
numbers, then:
<Edit> <Replace>
In the "Find What" window,
Hold down <Alt>, and enter
0160
Using the numbers from the Num keypad, *not* the numbers under the function
keys.
Since this is a <Space>, you won't see anything displayed in the "Find What"
window.
Don't enter anything in the "Replace With" window.
Hit <Replace All>
This should remove those non-breaking spaces and convert your data to XL
recognizable numbers.