I am having an issue with
the .COPY method

If I run my procedure without an autofilter selection active (with
all rows shown) then all is fine.

However, if I chose to limit my view of records by setting on an
autofilter selection, then I get an 1004 error : Copy Method of
Range class failed.

The offending line is:
ActiveWorkbook.Sheets("Workbench").Range(sttmpwbrange).Copy
Worksheets(instrtargetws).Range(stroutrange)

The various variables stated in the line of code have good values
when I look at them via the debugger.

I am using Excel 2003.