I have a rather large workbook with multiple uses of LOOKUP over a variety of
worksheets. In some cases, the LOOKUP of a particular value occurs only on
one worksheet, in other cases LOOKUP of the same value may occur over several
spreadsheets.

The problem I've run in to today is that when the data is updated, the value
returned by LOOKUP may not be correct (it keeps the old value and doesn't
replace it with the new one). In this particular instance, I used LOOKUP on
two different worksheets, both looking up values from the same table; some of
the values being looked up were the same, some were different. Spreadsheet 1
updated to the new values when the data was changed, however Spreadsheet 2
did not and kept the old value (which is now incorrect).

I was able to correct it by "re-doing" the LOOKUP formula on Spreadsheet 2,
but that's not going to be very effective long term.

Any suggestions of what the problem might be?
--
Linda Peters