Reading and Writing, but not 'Rithmetic

I find that when I am engaged in writing a story, which is different than thinking about writing one, it is incredibly difficult for me to actively read stories. If I find a good old book, it does have the ability to drag me away to a comfortable chair and let me focus on reading, but I do not have the same focus for anything I read on a computer. It is just too easy to cave into the pressure of opening the wordprocessing tool and the text of what I am working on. At that point it is unfairly difficult for an author to fully grab my attention.

Do others experience this? Does it become easier to compartmentalize with more experience?