Office Web Components creating Merge Fields in Excel Performance

One of my programmers is using Office Web Components in classic ASP to
create, fill and format an Excel spreadsheet. Everything is fine except when
he creates Merged cells the performance drops dramatically. He has
investigated the 'Center Across Cells' alternative but cannot get it working
using Office Web Comonents.

Has anyone come across this problem or even better has a solution?

Mike

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Michael Hartshorn
Solutions Architect