Hello, I hope this problem description makes sense. If not, I can try
again.

I have a spreadsheet that imports data from a csv file. I've set up a
button to refresh the data from the csv file. The spreadsheet uses
columns A thru BS and then hides many of the columns to give an
"Inventory Report". This report shows columns like Item, Description,
Bin Location, On Hand, Cost, Last Sales, etc. The spreadsheet then
creates a final column titled "Extension" which is Cost x On Hand.
This final column, Extension, is a calculation and not imported from
the csv file.

At the top of the spreadsheet are two calculations - Total Inventory
Value with a formula of "=SUM(BT:BT)" and Value this View with a
formula of "=SUBTOTAL(9,BT:BT)".

This all works fine as long as the number of rows do not change (but
that is not the real world). If I initially import a file with 6000
records the spreadsheet works. If I then import a file of 8000
records, the spreadsheet works. But if I then import a file of 5000
records the Extension Column rows 5001 thru 8000 show "#REF!" or
"$0.00" and the totals at the top (Total Inventory Value and Value
this View) also show "#REF!". If I manually clear the contents of the
"#REF!" cells and the "$0.00" cells, the top formulas work. But this
clearing has to be an automatic process and cannot be done manually.

Any suggestions? All help is very much appreciated!!