What I actually did was set up custom goals so I can keep a more accurate count.

Just go to the goals link on the left, and set up one for carbs and one for fiber (so you can subtract out) - they don't even necessarily have to be set to any number (ie, you can stick them both at 1 if you want)

Then when you go into reports - click on "Am I meeting my custom goals for today" - it will give you a more accurate count of carbs and fiber. (ie, it will say 26.69 g carbs and 14.26 g fiber)