I've been scratching my head over this issue for several days now.....
I have a box, that is connected to a bar via a spring.
The box falls down, and the bottom hinges open, and a piece of text falls out of the box. This text element is also held by a spring.
I can't seem to get everything to work without one part of the dynamics simulation interfering with the other. In my example, I had to disable a hinge connector for the bottom of the box, and keyframe that. I'd rather have everything work dynamically. Once I get the first drop to work (with keyframes for the bottom hinge), I can't even get the text to drop without strange collision issues. I'm trying to a - get the second drop to work, then b - get the second spring connecting the text to the box to work, then c - somehow have the hinge on the bottom be dynamic as opposed to keyframed.
I'm hoping someone can take a look at my sample scene, and see something that will put me on the right path.
Dynamics can be quite tricky. The main problem in your file is that you have the main box's collision set to automatic, which in effect assigns a collision shape in the form of a solid cube. You need to set that "moving mesh".
I've played around with your file to get something close to what I think you're looking for. It's going to be tough because the spring connector's themselves don't recognize collisions. I made quite a few tweaks, including to the box and letter's damping settings. I made the hinge work by keyframing its angle limit.