Nancy - Here is a really great blog post I read today by someone who does not tolerate oats or gluten. ~ http://www.artofglutenfreebaking.com/
I have a severe almost immediate allergic reaction to gluten and I have never reacted to oats that have been certified gluten free. From what I understand there is a chance for oats to cross pollinate or to be contaminated by gluten containing cereal grains during transport. I use Bob's Red Mill certified gluten free oat flour and certified gluten free oats.
Another issue to be aware of (and the blog does well to explain this) is there is another protein in Oats that some people are sensitive to. ~ Hope this helps.