Adding "application.volatile" to the beginning of the UDF's appeared to
work. I didn't get the #VALUE error after opening the workbook. The
only problem I have with this method is the recalculating of all the
formulas. In a workbook there maybe thousands or tens of thousands of
these formulas that have to be recalculated and that can be time
consuming.

The UDF's that are giving me problems are a part of an third party
add-in. I would like to get the problem solved and suggest to the
author that the changes be implemented. If all of the formulas need to
be recalculated, many other users of this add-in may not appreciate
this fix. If I add this fix to my copy of the add-in only, then every
time I upgrade the add-in, I'll have to implement this line all over
again.

Thank you very much for the suggestion, but are there any other options?