I had the same problem some days ago. Juan Pablo González helped my out with this post:
"Si, conozco un caso... es muy extraño. Se puede solucionar corriendo este macro
Sub RemoveDropdowns()
Dim shp As Shape
For Each shp In Sheet1.Shapes
shp.Delete
Next shp
End Sub
pero con cuidado, si hay celdas con comentarios, Excel explota !
_________________
Regards,
Juan Pablo González
MrExcel.com Consulting "
(But be carefull : if there are cells with comments, Excel crashs)
HTH.