Thanks for the reply. I have since created a workaround for my issue, but it was an interesting delimma.
I had a drop down box which was populated by a named range. As the third party software (Excel Writer) populated data into Excel, the named range should have expanded to accomidate the data. When I had a macro attached to the drop down box, the named range failed to expand. When I took the macro out, it expanded properly and populated the drop down. The macro was simply a retrieve script designed to pull data associated with the choice in the drop down box. I even tried attaching a different, very basic macro to the box and got the same result. My workaround was to create a macro that fired upon opening the workbook to attach my retrieve macro to the box. Have you heard of anything like this happening? Thanks for any input.