IDE requires a gem file when one is not needed

Recently on my Windows box I upgraded to 4.0.2 which is the first time I noticed this. This is the issue:

I have a Sinatra app for which I have been able to "run" the file and the server starts fine. In my case I'm using thin as my rack compliant web server. Yesterday , it started complaining about not being able to find "sinatra" i.e.

require "sinatra"

and it thus stopped allowing me to start the Sinatra server.

Sinatra is indeed in the path and it has been for a while which is confirmed by gem list

If I run the file from the command prompt it starts fine.

It eventually dawned on me that the IDE must be respecting the project gem file for which I did not have sinatra specified. Once I included "sinatra" it stopped whinning about not finding "sinatra" but then I encoutered issues with Thin and namely event machine. Again, al of this had been previously done and months ago via doing "gem install etc" including the native compilation via DevKit.

I then decided to totally wipe out my gemfile and lock file and to invalidate caches just in case. However, RubyMine still seems to care where it did not again care before.

Now, if I start a brand new project and specify a file with a sinatra require , I can "run" that file just fine.

How do I get past this ?

thanks

-Charles