RPS Include Content adds the requesting post (in this case your home page) to an array that is used to test for infinite loops. If post 1400 does not have an include that references the home page (or any other page for that matter), the error state should not be triggered.
We tested the plugin by adding the shortcode to a text widget just as you did, but were unable to reproduce the problem. Of course our sandbox testing environment (WordPress 3.4.2, Twenty Eleven theme, RPS Include Content 1.0.9) is likely different from your specific installation so there are many variables that were not considered.
Would it be possible for you to enable another comparable theme? If the problem continued then we would suggest narrowing down the issue by disabling plugins until you identify the conflict. That would give us the information that we need to go on to troubleshoot the problem further. Thanks for your efforts and keep us posted.