Reference levels not showing up even if they are turned on

I am using Power GEOPAK, I know its technically GEOPAK but this is a MicroStation function. Sometimes when I access a file, levels will not show up in the reference file even though they were there when first attached and the level display shows it being toggled on? I have to detach the reference and then reattach then the levels shows up. Any idea as to why this is happening?