I have implemented a wonderful RTD Server in c# that works like a dream.

However, After you open Excel, enter the RTD formula (You then get the
MSCoree.dll contains macros prompt - to which you answer yes) and get a
result. If you then close the workbook, so that Excel has no book open, and
then start a new workbook and type the same formula in you just get #N/A ???

I cannot for the life of me work out why. The only way to get the RTD
formulae working again is to close Excel and open it again.

Any Ideas anyone??