I'm not sure. I've re-read again your first post. What I understand is that you're trying to place a blank space of 960 pixels inside a column, but you're getting just 40 pixels wide. That was my conclussion because (if I'm correct) you're trying to get a 960px wide area but at the same time you're trying to hide the image. For what I know, if an element is set as 'hidden' it'll not show... not even a blank space.
Is that what you're trying to achieve? If that's the case I still think that you have to play with the column width if you keep the image hidden, or with the image opacity and not using the hidden property.
Another thing, if the image is inside a column, then I suppose that you mean inside a table, so you may have to check the configuration for table, tr and td elements (table, row and cell) just to be sure none of them are giving you trouble.
Sorry in advance if none of this pointers help you.
Good luck!