There is already some posts on this subject, sometimes images seem to get embedded into the project file and impossible to get rid of, this happened to me when I deleted a column with images in the text objects. I think that I should have deleted the images first, then deleted the text objects, then deleted the column, in that order, so now I make sure I delete the image first before deleting the object.

It would be good if incromedia could create a tool to help clean up redundant images in projects.