If you are having issues getting Web Intelligence to export to Excel with out merging its usually due to header fields on the top of the table ending at a right position that is in between the start and end position of the column below.

To align measurement in webi set measurement to pixels and set the widths even numbers

The following guidelines must also be followed in order for header cells to export correctly in Excel:
Position header cells per the instructions below:

  1. Change to structure view.
  2. Drag the main table into the report body below its present position in the header
  3. Ensure all cell headers are placed below the page header section and above the main table
  4. Align all header cells using relative positioning so that their end points end at same place as header cells.
  5. Click on the whitespace at the page bottom.  Deselect "show page header" to suppress the header in the Excel export