John,

It might be a long shot, but try using

With ThisWorkbook.Worksheets("Sheet1")


--
Cordially,
Chip Pearson
Microsoft MVP - Excel
Pearson Software Consulting, LLC
www.cpearson.com



"John H" wrote in message
...
The sheet has been named the same for at least five years. I
have not tried changing its name since it is used in over 500
formulas using Excel functions. The name works in Excel
functions, just not in VBA functions, while other worksheet names
work in both. Also, the worksheet is NOT hidden.

John H