Im marlin preferences I click on "Make my default file manager", but nothing changed. All apps like Chrome or Skype still open Nautilus like default. Thanx for any help.
This question was asked of the Marlin maintainer on Ubuntu Launchpad at the end of May 2011. This is the link to the answer that was marked as solved.
Notice this answer given by the maintainer on the first of June 2011:
A similar question was asked again on 10th December 2011 and also marked as solved. Here is the link.
So, you are using an application that is still being developed and is perhaps fit for testing but not yet ready for being a Nautilus replacement. It may work fine as a simple file manager but Nautilus does more than browse files and folders. This is why Nautilus stills opens when you perform the actions that you describe.
It also seems that Marlin is more suited to the Xfce desktop environment than the Gnome environment whether Gnome 2 or Gnome 3
Here is a link to the exo-utils package mentioned in the other links. Notice this description:
The only other thing I can add is that you will find the exo-utils package in the Ubuntu software Centre but notice that it is listed as being an Xfce settings plugin. You are not using Xfce. Is this the cause of your problem and the answer?
Regards and happy testing