The reason this is important to editors is because it maintains the length of your timeline.
I agree with Alex, if you are going to use CS3’s single track editing, your best bet is to plan ahead and mark your in and out points 15 frames +/- for 1 sec crossfades.
Or… it really shouldn’t be too time consuming to continue to work the way you are, and ripple edit each crossfade from the timeline 15 frames in and out after the fact. With snap turned on it should be a breeze.
BTW, Premiere 6.5 has a 2 track editing mode if you can get a hold of that. But you’ll notice the workflow is not as efficient when making revisions to your edit.