Text style issue - slant

We here at our office have several text styles that we use. One in particular uses the Working text font and we like to have it at a slant of 18 degrees. I have it set up in the text styles list for its height, width, color, slant angle, etc. I have italics checked. But when I select this text style and then type in a value, sometimes its slanted, sometimes it isnt. Sometimes when its a single line, its slanted, but when its multi line it isnt. Sometimes its the opposite. I cant figure it out. I have to manually change the slant angle in change text attributes. Does anyone have any suggestions?