I'm using this function in Excel '07 to return the worksheet name into cell
B1 on a sheet.

=RIGHT(CELL("filename",$A$1),LEN(CELL("filename",$ A$1))-FIND("]",CELL("filename",$A$1)))

If the sheet name is "WORKSHEET", every so often the function returns
".xlsm]WORKSHEET. This usually occurs when I go to another worksheet, then
come back to this one. When I go into the cell (F2) then hit enter, it
corrects itself.

I have calculation set to automatic.

The workbook size is only about 16MB.

Any ideas?