New Post: Background colour of cells being lost

Hi,

I am opening an existing excel file to use as a template. There is a grey background in the template surrounding a "form" in each worksheet.

After setting values of certain cells within the form area (which no not have a Fill), the background colour of random cells outside of the form are lost.

Is there anything which could be causing this? I know I could programmatically set the fill, but this would be very tedious and hard to maintain. I'm wondering if I'm doing something the wrong way which could cause this.

It's worth pointing out that I am not adding any new rows or columns. They are in a fixed position.

Thanks
John