Forget it. It's solved. I don't understand this bizarre thing really, but I installed poseidon and trident in another HD CF I have and now it works.
The only thing I find could be culprit is the AmigaAmp program. I had it already installed with a direct access through Sys4Aga on the screen, but as I didn't like the skin, I downloaded another version and changed the drawers with the new ones, making the new AmigaAmp being opened using that Sys4Aga direct access.
In the other HD I have the old version (or perhaps it's the same with a different skin?) of AmigaAmp and it's the one that works.
So I will change again the program in the other HD and if I want to change the skin will use another way.
Perhaps it can be other thing, because I've noticed a lot of crashes in the usual HD, but no one with the other. I believe I will change the system information from one to another.
EDIT:
Well, I've been too fast to say that. In fact it works with the system copy, but after I installed a couple of things it has started to make the same, this time with the old AmigaAmp program. I have to see one by one which of the adds I make to that System copy makes AmigaAmp make that.