How do I keep a cloth simulation from interacting with a particle emitter, while still interacting with the particles? I'm trying to work with a cloth simulation that encloses a particle system.  Unfortunately, I can't get the cloth to be deformed by the particle system, while ignoring the particle emitter (I'm also using the Molecular Script to apply physics to the particles, http://pyroevil.com/molecular-script-docs/).  In this case, I created two simple cubes to illustrate the problem, a cloth simulation cube surrounding a particle emitter cube.  Wireframe image



edit - I tried setting the particles to Global and then moved the dupli-object, which solved the emitter problem, but then the cloth wouldn't interact with the particles.

edit - I also tried activating a cloth simulator on just the particle emitter.  That didn't work either, although it could be a setting I'm missing.  The cube does emit the particles and it does deform with the cloth simulation, but the particles don't interact with it. (I tried this after I uploaded the .blend file.  I will upload a new .blend if I get closer to a solution).

I've added a simple .blend file that will hopefully illustrate the issue (Molecular Script needed to see the full idea, but shouldn't be necessary to see the problem).  

I was actually able to get the Molecular simulation to work properly, by taking the top off of the cloth cube.  I didn't include those settings in this .blend file though.  For those that might download this one, the settings are really off.
You can do as follows:


Add a loop cut right in between the cube (cloth).
Delete the following lines:

Change the "Element to Snap to" to vertex.
Then Extrude the following highlighted lines towards the middle while stopping at each loop cut:



If all steps are done correctly the bag should open up like this:


NOTE: The more lines you delete in step 2 the wider the bag will open up.

BTW Here is the solved file: