I've got a worksheet ('1') that has a column of dates ("dd/mm/yyyy hh:mm") which is not linked from anything (it's just a list) and another column with 'values' corresponding to those date/time stamps.
A second worksheet ('2') has date/time and 'values' pulled in from an outside source (OSISOFT PI). I want a third worksheet to match the date time 'values' for the first worksheet
In this third worksheet ('3') I have the date/time range in column A taken from the second worksheet because it is a dynamic date/time range. the 'values' are for argument sake in column 'B'.
The problem is that it matches (or finds) some of the values but not all. For example:

.
.
01/01/2015 00:10 313.7
01/02/2015 00:20 315.7
01/02/2015 00:30 #N/A
01/02/2015 00:40 314.9
01/02/2015 00:50 313.7
01/02/2015 01:00 #N/A
.
.
I've gone through and tried to find "phantom characters", but can't see anything . What confuses me is that it seems to work for some values and not others.

Can anyone help with this?