I have the following formula in Excel 2000, which normally works fine:-

=VLOOKUP(E2,$U$2:$V$24,2,FALSE)

I have a long list of values in column E with a matching formula in column F
to return a category. Every month I get a new set of values in column E,
which I would like to copy and paste from an external source (previous
version of Excel spreadsheet). When I do a Paste or Paste Special Values, the
VLOOKUP formula returns #N/A. If I overtype the pasted value with the number
shown, the formula works again.

I have tried using INDEX and MATCH instead of VLOOKUP and I get the same
problem.