Hi,
I have tried three different codes & get the same strange problem.
I have two columns A & B.
My code/s compare the serial numbers in column A with column B and
returns;
what numbers column A has that column B hasn't to 'result column' D
what numbers column B has that column A hasn't to 'result column' E

This works fine when I type the serial numbers into A & B myself by
hand, however,
when I import the list of numbers into column A (copy & paste from
someone elses file)
it returns incorrect results ie. it returns serial numbers that exist
in both columns to both results columns!
That is strange enough in itself but it gets stranger;
I can rectify the problem simply by retyping the serial number in each
cell in column A?
For example, if after running the code B1P04599 wrongly appears in all
four columns, I simply type over B1P04599 in column A, run the code
again & B1P04599 no longer appears in columns D & E?
Anyone got any ideas what is causing this strange behaviour?

Thanks for your help.