Combo Box doesn't display text in linked cell
 

I have used a macro to set the value of a number of cells which are the
linked cells of a number of combo boxes. Some of the boxes display the value
that the code has set, others do not. Unless I have missed something subtle,
all the boxes have the same property settings. Is there a way for forcing
the boxes to dislpay the value of their linked cell such as a "repaint"?
It is a very large workbook with 112 sheets so I am suspicious that I am in
the land of memory trouble again. Any thoughts?