Delete Qty column in BOM?

Hi,

I'm using SW2010 and am trying to set different BOM's for parts and assemblies. For my part BOM I don't want the Qty column to appear as it is always '1' for the part and this is meaningless. When I right click>delete>column nothing happens for the Qty column. All other columns delete normally using this process.

Anyone else experienced this?

Thanks,

Sam

SolidworksBill Of Materials